A type of isthmus crack fixing device

Abstract

This utility model provides a fixation device for isthmic fractures, belonging to the field of medical device technology. The isthmic fracture fixation device provided by this utility model includes a pedicle screw, a laminar hook, and a bone plate. The tail end of the pedicle screw is provided with a mounting base. The laminar hook includes a rod and a hook, with the hook located at the lower end of the rod and facing the vertebral body. The upper end of the rod passes through the mounting base. The upper end of the bone plate is provided with a locking hole, through which the pedicle screw passes, fixing the bone plate to the posterior wall of the vertebral body. This isthmic fracture fixation device, with its bone plate fixed to the posterior wall of the vertebral body by the pedicle screw, increases the stability of the device.

Description

Technical Field

[0001] This utility model belongs to the field of medical device technology, specifically relating to a fixation device for isthmus fracture. Background Technology

[0002] Spondylolysis is a common spinal injury, primarily caused by congenital factors and traumatic stress, resulting in discontinuity or fracture of the pars interarticularis of the lumbar vertebrae. It typically manifests as damage or fracture of the vertebral pars interarticularis between the articular processes of one or both lumbar vertebrae. Because young people have thinner bone in the pars interarticularis, weaker intervertebral disc shear resistance, and less robust lumbosacral muscles, they are particularly susceptible to stress fractures during high-intensity exercise. Therefore, spondylolysis has a high incidence rate in youth, especially among those who engage in strenuous exercise or excessive labor. Symptoms of spondylolysis include lower back pain, buttock and thigh pain, and numbness, leading to limited mobility. Without timely and effective treatment, it can result in intervertebral disc degeneration, disc herniation, and even vertebral slippage, causing lower limb walking and bowel and bladder dysfunction. Treatment for lumbar spondylolysis can be conservative or surgical. Surgical treatment generally involves direct repair of the spondylolysis. Currently, the widely used direct repair technique combines spondylolysis fusion with single-segment internal fixation. This addresses the stress shielding effect of cross-segment internal fixation on adjacent segments. During treatment, a laminar hook-pedicle screw fixation system can be used. The pedicle screw at the base of the superior articular process connects to the laminar hook, providing secure fixation and facilitating fusion. Postoperatively, patients can ambulate early. Single-segment fixation of the lumbar vertebral motion segment does not affect lumbar segmental movement, has minimal impact on adjacent segments, and allows for a large bone graft area, high fusion rate, and excellent therapeutic effect. In the other method, a pedicle screw is implanted at the base of the superior articular process, and the laminar hook is hooked to the lower edge of the lamina at the same segment. The two are connected by a connecting bar, and pressure is applied by adjusting the screws on the connecting bar. However, the fit between the laminar hook and the lumbar lamina is relatively poor, affecting the fixation effect. Utility Model Content

[0003] The purpose of this invention is to provide a fixation device for isthmus fracture, which aims to solve the problem of poor fit between the lamina hook-pedicle screw fixation system and the lumbar lamina.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a pars interarticularis fixation device is provided, including a pedicle screw, a lamina hook, and a bone plate. The tail of the pedicle screw is provided with a mounting base. The lamina hook includes a rod and a hook. The hook is located at the lower end of the rod and faces the vertebral body. The upper end of the rod passes through the mounting base. The upper end of the bone plate is provided with a locking hole. The pedicle screw passes through the locking hole to fix the bone plate to the posterior wall of the vertebral body.

[0005] In one possible implementation, the bone plate is fitted to the posterior wall of the vertebral body.

[0006] In one possible implementation, the bone plate is fitted to the posterior wall of the vertebral body.

[0007] In one possible implementation, the two sets of fixing holes are arranged along the length of the bone plate.

[0008] In one possible implementation, the fixation pin is inserted into the inferior articular process.

[0009] In one possible implementation, the rear end of the pedicle screw is provided with a universal ball head, which matches the front end of the mounting screw seat. The mounting screw seat is provided with a limiting seat, which is located on the rear side of the universal ball head to limit the universal ball head.

[0010] In one possible implementation, the rear end of the limiting seat is provided with a relief groove suitable for accommodating the upper end of the rod.

[0011] In one possible implementation, a locking seat is provided within the mounting pin holder, the locking seat being located on the rear side of the vertebral plate hook, thereby limiting the upper end of the rod portion within the mounting pin holder.

[0012] In one possible implementation, the locking seat is threadedly engaged with the mounting pin seat.

[0013] In one possible implementation, the lower end of the bone plate is located above the lower end of the lamina hook.

[0014] The beneficial effects of the isthmus crack fixing device provided by this utility model are as follows:

[0015] Compared with existing technologies, this device includes a pedicle screw, a laminar hook, and a bone plate. The pedicle screw is implanted at the base of the superior articular process, with the mounting base located at the tail of the pedicle screw. The laminar hook includes a rod and a hook connected sequentially. The rod of the laminar hook passes through the mounting base and is confined within it. The hook of the laminar hook extends downward and hooks onto the lower edge of the lamina of the same segment. The upper end of the bone plate has a locking hole through which the pedicle screw passes to fix the bone plate. The bone plate is located on the posterior wall of the vertebral body, which helps to strengthen the fixation of the device to the vertebral body and helps to improve the patient's recovery rate. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A three-dimensional structural diagram of the isthmus crack fixing device provided in the embodiment of this utility model. Figure 1 ;

[0018] Figure 2 A three-dimensional structural diagram of the isthmus crack fixing device provided in the embodiment of this utility model. Figure 2 ;

[0019] Figure 3 An exploded structural diagram of the isthmus crack fixing device provided in an embodiment of this utility model.

[0020] In the diagram: 1. Pedicle screw; 2. Universal ball head; 3. Bone plate; 4. Fixation screw; 5. Guide slope; 6. Lamina hook; 7. Rod; 8. Contraction section; 9. Hook; 10. Fixation cone; 11. Mounting screw seat; 12. Limiting seat; 13. Locking seat; 14. Rotation groove. Detailed Implementation

[0021] To make the technical problems, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0022] It should be noted that when an element is referred to as "fixed to" or "set on" another element, it can be directly or indirectly on the other element. When an element is referred to as "connected to" another element, it can be directly or indirectly connected to the other element. It should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application 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 this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0023] Please refer to Figures 1 to 3 The present invention provides a specific embodiment of a fixation device for isthmic fracture, comprising a pedicle screw 1, a lamina hook 6, and a bone plate 3. The tail of the pedicle screw 1 is provided with a mounting base 11. The lamina hook 6 includes a rod 7 and a hook 9. The hook 9 is located at the lower end of the rod 7 and faces the vertebral body. The upper end of the rod 7 passes through the mounting base 11. The upper end of the bone plate 3 is provided with a locking hole. The pedicle screw 1 passes through the locking hole to fix the bone plate 3 to the posterior wall of the vertebral body.

[0024] This utility model provides a pars interarticularis fixation device, which, compared with the prior art, includes a pedicle screw 1, a lamina hook 6, and a bone plate 3. The pedicle screw 1 is used for implantation at the base of the superior articular process. The mounting base 11 is located at the tail of the pedicle screw 1. The lamina hook 6 includes a rod 7 and a hook 9 connected in sequence. The rod 7 of the lamina hook 6 passes through the mounting base 11 and is confined within the mounting base 11. The hook 9 of the lamina hook 6 extends downward and hooks onto the lower edge of the lamina of the same segment. The upper end of the bone plate 3 is provided with a locking hole. The pedicle screw 1 passes through the locking hole to fix the bone plate 3. The bone plate 3 is located on the posterior wall of the vertebral body, which helps to strengthen the fixation of the vertebral body by the device and helps to improve the patient's recovery rate.

[0025] For details, please refer to Figures 1 to 3The posterior wall of the vertebra is defined as the side of the vertebra with the superior articular process, and the anterior wall of the vertebra is defined as the side of the vertebra away from the superior articular process. The anterior-posterior direction of the device is defined by the anterior-posterior direction of the vertebra. The isthmic fracture fixation device includes a pedicle screw 1, a laminar hook 6, and a bone plate 3. The mounting base 11 is located at the tail of the pedicle screw 1, and the tail of the pedicle screw 1 is located inside the mounting base 11, while the tail of the pedicle screw 1 is located at the front end of the mounting base 11. The frontal side wall of the mounting base 11 is suitable for the pedicle screw 1 to pass through. The pedicle screw 1 has threads on its body. The diameter of the tail of the pedicle screw 1 is larger than the diameter of the body of the pedicle screw 1 to prevent the pedicle screw 1 from detaching from the mounting base 11 during use, thus increasing the stability of the device. The bone plate 3 is located in front of the mounting base 11. The upper end of the bone plate 3 has a locking hole. The body of the pedicle screw 1 passes through the locking hole at the upper end of the bone plate 3 and is implanted at the base of the superior articular process. The mounting base 11 helps to limit the bone plate 3 to the posterior wall of the vertebra. The lamina hook 6 includes upper and lower connecting parts. The lamina hook 6 has a rod portion 7 and a hook portion 9. A contraction portion 8 is provided between the rod portion 7 and the hook portion 9. The rod portion 7 is located at the upper end of the contraction portion 8, and the hook portion 9 is located at the lower end of the contraction portion 8. The diameter of the contraction portion 8 gradually decreases as it approaches the hook portion 9. The upper end of the rod portion 7 of the lamina hook 6 passes through the mounting nail seat 11. The upper end of the rod portion 7 of the lamina hook 6 is provided through the side wall of the mounting nail seat 11. The rod portion 7 of the lamina hook 6 is located on the posterior side of the tail of the pedicle screw 1 away from the vertebral body. The lamina hook 6 is located on the posterior side of the bone plate 3. The hook portion 9 of the lamina hook 6 faces... The vertebral body is hooked onto the lower edge of the lamina of the same segment. The hook portion 9 of the lamina hook 6 has an arc that matches the lower edge of the vertebra. A fixing tip 10 is provided on the side wall of the hook portion 9 near the vertebra. There are two sets of fixing tips 10, which are arranged along the width of the hook portion 9. The fixing tips 10 are conical and can be nailed into the vertebral body, which helps to fix the hook portion 9 to the vertebral body and prevent the lamina hook 6 from falling off. The bone plate 3 works with the lamina hook 6 to improve the stability of the device fixation and help the patient recover.

[0026] As a specific embodiment of the isthmus crack fixing device provided by this utility model, please refer to Figures 1 to 3 The bone plate 3 is fitted to the posterior wall of the vertebral body.

[0027] For details, please refer to Figures 1 to 3 The anterior wall of the bone plate 3 fits against the posterior wall of the vertebral body. The shape of the bone plate 3 conforms to the physiological curve of the vertebral body. The bone plate 3 extends along the direction of the laminae hook 6. The edge of the bone plate 3 is curved. In order to match the physiological curve of the vertebral body, the middle part of the bone plate 3 is concave forward relative to the upper and lower ends. The width of the widest part of the lower end of the bone plate 3 is greater than the width of the widest part of the upper end of the bone plate 3, which improves the fit between the bone plate 3 and the posterior wall of the vertebral body and increases the stability of fixation.

[0028] As a specific embodiment of the isthmus crack fixing device provided by this utility model, please refer to Figures 1 to 3 The bone plate 3 has a fixing hole, and a fixing nail 4 is inserted into the fixing hole.

[0029] For details, please refer to Figures 1 to 3 A fixation screw 4 is provided on the bone plate 3. The fixation screw 4 passes through the fixation hole provided on the bone plate 3 and enters the patient's vertebral body. The fixation hole is located at the lower end of the bone plate 3. The fixation screw 4 is located below the pedicle screw 1, which helps to enhance the stability of the vertebral body fixation. The tail of the fixation screw 4 is provided with a holding groove. The holding groove is located at the center of the tail of the fixation screw 4. The holding groove is suitable for the insertion of tools and helps to hold the fixation screw 4, which helps to implant the fixation screw 4 into the patient's vertebral body. The fixation screw 4 includes a tail and a screw part connected together. The tail of the fixation screw 4 is located at the rear end of the screw part of the fixation screw 4. The outer wall of the tail of the fixation screw 4 is provided with a guide slope 5. The guide slope 5 is arranged around the tail of the fixation screw 4. Under the action of the guide slope 5, the diameter of the tail of the fixation screw 4 gradually decreases as it gets closer to the screw part of the fixation screw 4, which facilitates the implantation of the fixation screw 4.

[0030] As a specific embodiment of the isthmus crack fixing device provided by this utility model, please refer to Figures 1 to 3 Two sets of fixing holes are set along the length of bone plate 3.

[0031] For details, please refer to Figures 1 to 3 There are two sets of fixing holes, which are distributed vertically along the length of the bone plate 3 to increase the stability of the bone plate 3 during installation.

[0032] As a specific embodiment of the isthmus crack fixing device provided by this utility model, please refer to Figures 1 to 3 Fixation pin 4 is inserted into the inferior articular process.

[0033] For details, please refer to Figures 1 to 3 Fixation nail 4 can penetrate into areas with more bone, including the inferior articular process, thereby increasing the stability of the fixation nail 4 implantation.

[0034] As a specific embodiment of the isthmus crack fixing device provided by this utility model, please refer to Figures 1 to 3 The rear end of the pedicle screw 1 is provided with a universal ball head 2, which matches the front end of the mounting base 11. The mounting base 11 is provided with a limiting seat 12, which is located on the rear side of the universal ball head 2 to limit the universal ball head 2.

[0035] For details, please refer to Figures 1 to 3The universal ball head 2 is located at the rear end of the pedicle screw 1 and inside the mounting base 11, at the front end of the mounting base 11. The side wall of the front end of the mounting base 11 matches the universal ball head 2. The angle between the mounting base 11 and the pedicle screw 1 is adjustable. The angle of the mounting base 11 can be adjusted according to the actual installation situation. The limiting seat 12 is located inside the mounting base 11. The front side wall of the limiting seat 12 matches the universal ball head 2. The limiting seat 12 presses the universal ball head 2, which helps to lock the position and angle of the mounting base 11.

[0036] As a specific embodiment of the isthmus crack fixing device provided by this utility model, please refer to Figures 1 to 3 The rear end of the limiting seat 12 is provided with a relief groove suitable for accommodating the upper end of the rod 7.

[0037] For details, please refer to Figures 1 to 3 The mounting base 11 has a clearance groove on its side wall. The clearance groove is set along the length of the mounting base 11 and is a U-shaped groove. The opening of the clearance groove is set at the rear end of the mounting base 11 away from the pedicle screw 1. There are two sets of clearance grooves, which are set opposite to each other. The upper end of the rod 7 passes through the two sets of clearance grooves to facilitate the installation of the vertebral plate hook 6.

[0038] As a specific embodiment of the isthmus crack fixing device provided by this utility model, please refer to Figures 1 to 3 A locking seat 13 is provided inside the mounting nail seat 11. The locking seat 13 is located on the rear side of the vertebral plate hook 6, which limits the upper end of the rod 7 inside the mounting nail seat 11.

[0039] For details, please refer to Figures 1 to 3 The locking seat 13 is located inside the mounting nail seat 11. The locking seat 13 is located on the rear side of the rod 7 away from the pedicle screw 1. The rear side wall of the limiting seat 12 matches the shape of the rod 7. The front side wall of the locking seat 13 matches the shape of the rod 7. The locking seat 13 presses the rod 7 of the lamina hook 6 tightly onto the limiting seat 12.

[0040] As a specific embodiment of the isthmus crack fixing device provided by this utility model, please refer to Figures 1 to 3 The locking seat 13 is threadedly engaged with the mounting pin seat 11.

[0041] For details, please refer to Figures 1 to 3 The outer wall of the locking seat 13 and the inner wall of the mounting pin seat 11 are threaded together to increase the stability of the device. The rear wall of the locking seat 13 is provided with a rotating groove 14 to facilitate the rotation of the locking seat 13.

[0042] As a specific embodiment of the isthmus crack fixing device provided by this utility model, please refer to Figures 1 to 3 The lower end of the bone plate 3 is located above the lower end of the lamina hook 6.

[0043] For details, please refer to Figures 1 to 3 The lower end of the laminae hook 6 is located below the lower end of the bone plate 3, and the bone plate 3 is located in front of the laminae hook 6.

[0044] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An apparatus for cleft fixation, comprising: The device includes a pedicle screw, a laminar hook, and a bone plate. The tail of the pedicle screw is provided with a mounting base. The laminar hook includes a rod and a hook. The hook is located at the lower end of the rod and faces the vertebral body. The upper end of the rod passes through the mounting base. The upper end of the bone plate is provided with a locking hole. The pedicle screw passes through the locking hole to fix the bone plate to the posterior wall of the vertebral body.

2. An apparatus for cleft fixation as defined in claim 1, wherein, The bone plate is fitted to the posterior wall of the vertebral body.

3. An apparatus for cleft fixation as defined in claim 1, wherein, The bone plate is provided with fixing holes, and fixing nails are inserted into the fixing holes.

4. An apparatus for cleft fixation as defined in claim 3, wherein, The two sets of fixing holes are arranged along the length of the bone plate.

5. An apparatus for cleft fixation as defined in claim 3, wherein, The fixation pin is inserted into the inferior articular process.

6. An apparatus for cleft fixation as defined in claim 1, wherein, The rear end of the pedicle screw is provided with a universal ball head, which matches the front end of the mounting screw seat. The mounting screw seat is provided with a limiting seat, which is located on the rear side of the universal ball head to limit the universal ball head.

7. An apparatus for cleft fixation as defined in claim 6, wherein, The rear end of the limiting seat is provided with a relief groove suitable for accommodating the upper end of the rod.

8. An apparatus for cleft fixation as defined in claim 7, wherein, A locking seat is provided inside the mounting nail seat. The locking seat is located on the rear side of the vertebral plate hook and limits the upper end of the rod within the mounting nail seat.

9. An apparatus for cleft fixation as defined in claim 8, wherein, The locking seat is threadedly engaged with the mounting pin seat.

10. An apparatus for cleft fixation as defined in claim 1, wherein, The lower end of the bone plate is located above the lower end of the lamina hook.

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