Lag screw for treating lumbar spondylolysis

Abstract

The lag screw comprises a screw rod, a nut and a thread, a screw tip comprises two tip bodies, and a plum blossom groove is formed in one end of the screw rod. The screw tip comprises the two tip bodies, so that the penetrating capacity of the lag screw for treating lumbar spondylolysis is improved, vertebral pedicle cortex can be just punctured, the risk of lower limb pain caused by nerve injury can be reduced, and the screw can be screwed more conveniently and rapidly; and the plum blossom groove is formed in one end of the screw rod, so that the holding force of the screw is better when the screw is tightened and taken out, the risk that the contact point slips is effectively reduced, and the lumbar vertebra isthmus healing is facilitated.

Description

Technical Field

[0001] This application relates to the field of medical technology, and in particular to a tension screw for treating lumbar spondylolysis. Background Technology

[0002] In 1968, Kimura first proposed the concept of direct repair of pars interarticularis fracture, a surgical method involving bone grafting at the pars interarticularis fracture site without any internal fixation. In 1970, Buck first reported the use of penetrating screws for internal fixation during pars interarticularis fracture treatment, known as the translaminar lag screw (Buck) technique. This technique provides effective fixation for pars interarticularis fractures and achieves good healing rates. In recent years, with advancements in technology and updated materials, several specialists have made slight improvements to this technique, but the surgical steps remain similar. After accurate intraoperative fluoroscopic positioning, the scar tissue and sclerotic tissue at the pars interarticularis fracture site are treated with a curette and burr until minimal bleeding occurs. After implanting autologous bone at the pars interarticularis fracture site, the needle is inserted 8 mm lateral to the midline of the lower edge of the vertebral lamina at the segment where the pars interarticularis fracture is located. The needle is then inserted at a 10° outward and 30° upward inclination, creating an opening and pathway that passes through the pars interarticularis fracture site, extending towards the upper outer edge of the pedicle. The bone graft and fracture ends are longitudinally compressed using tension screws to restore the continuity of the isthmus.

[0003] During intraoperative and postoperative imaging examinations, we discovered several design flaws in the hollow lag screws currently used by various medical device manufacturers. For example, the screw length and thread coverage area do not conform to anatomical studies of lumbar spondylolysis. Excessive length increases the risk of screw placement problems, while insufficient length makes it difficult to apply adequate pressure to the lumbar pars interarticularis. The thread design also directly affects the screw's pull-out resistance. Currently, screw loosening and breakage are significant concerns, but there is still no specific lag screw designed for lumbar pars interarticularis. These flaws increase the risk of screw loosening and breakage, as well as reduced pull-out resistance, ultimately leading to lumbar pars interarticularis nonunion. Summary of the Invention

[0004] The present invention introduces a series of simplified concepts, which will be further explained in detail in the detailed description section. This part of the present invention is not intended to limit the key features and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art or related technologies.

[0006] In view of this, this application provides a tension screw for treating lumbar spondylolysis, comprising: a screw rod, a nut, and a thread, wherein the nut is disposed at one end of the screw rod, and the thread is disposed on the screw rod;

[0007] The screw has a screw tip at the end opposite to the nut, and the screw tip includes two pointed bodies;

[0008] The nut has a perforated groove at the end opposite to the screw.

[0009] In one feasible implementation, the plum blossom groove includes a groove body and a plurality of groove petals connected to the groove body, the plurality of groove petals being evenly arranged on the periphery of the groove body, and the inner wall of each groove petal being arc-shaped.

[0010] In one feasible implementation, the length of the screw is 32mm to 40mm;

[0011] The thickness of the nut is 2mm to 3mm;

[0012] The length of the thread covering the screw is 12 mm to 20 mm.

[0013] The diameter of the screw is 2.5 mm to 3.5 mm;

[0014] The outer diameter of the thread is 4 mm to 4.5 mm.

[0015] In one feasible implementation, the length of the screw is 38 mm;

[0016] The thickness of the nut is 2.5.

[0017] The thread covers a length of 15 mm on the screw.

[0018] The diameter of the screw is 3mm;

[0019] The outer diameter of the thread is 4.5 mm.

[0020] In one feasible implementation, the thread is a double thread with a pitch of 1 mm to 2 mm, a total number of 7 to 12 turns, triangular threads, a distal end inclination angle of 50° to 70°, and a proximal end inclination angle of 60° to 80°.

[0021] In one feasible implementation, the pitch is 1.5 mm, the total number of turns is 10, the threads are triangular, the distal end tilt angle is 50° to 60°, and the proximal end tilt angle is 70°.

[0022] In one feasible implementation, a groove is formed between two adjacent tips, the depth of which is 0.46 mm.

[0023] Compared with the prior art, the present invention has at least the following beneficial effects:

[0024] The tension screw for treating lumbar spondylolysis provided in this application includes a screw, a nut, and threads. The screw tip includes two pointed bodies, and one end of the screw has a perforated groove. The two pointed bodies at the screw tip improve the penetration capability of the tension screw for treating lumbar spondylolysis, allowing it to just penetrate the pedicle cortex, reducing the risk of nerve damage and lower limb pain, and making tightening the screw easier. The perforated groove at one end of the screw provides better holding force during tightening and removal, effectively reducing the risk of stripping at the contact point and promoting healing of the lumbar spondylolysis.

[0025] The above description is merely an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this utility model more obvious and understandable, specific embodiments of this utility model are given below. Attached Figure Description

[0026] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0027] Figure 1 A schematic structural diagram of the first angle of a tension screw for treating lumbar spondylolysis according to an embodiment of this application;

[0028] Figure 2 A schematic structural diagram of the second angle of a lag screw for treating lumbar spondylolysis according to an embodiment of this application;

[0029] Figure 3 A schematic structural diagram of the third angle of a tension screw for treating lumbar spondylolysis according to an embodiment of this application;

[0030] Figure 4 A schematic structural diagram of the fourth angle of a tension screw for treating lumbar spondylolysis according to an embodiment of this application.

[0031] in, Figures 1 to 4 The correspondence between the reference numerals and component names in the attached drawings is as follows:

[0032] 110 screw, 120 nut, 130 thread;

[0033] 121 plum blossom groove, 1211 groove body, 1212 groove petal;

[0034] 131 screw tip, 1311 pointed body, 1312 groove. Detailed Implementation

[0035] The following description provides numerous specific details to offer a more thorough understanding of the technical solutions provided by this invention. However, it will be apparent to those skilled in the art that the technical solutions provided by this invention can be implemented without one or more of these details.

[0036] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to the present invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of the stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or combinations thereof.

[0037] Exemplary embodiments according to the present invention will now be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. It should be understood that these embodiments are provided so that the disclosure of the present invention is thorough and complete, and that the concept of these exemplary embodiments is fully conveyed to those skilled in the art.

[0038] This application provides a tension screw for treating lumbar spondylolysis, comprising: a screw 110, a nut 120, and a thread 130. The nut 120 is disposed at one end of the screw 110, and the thread 130 is disposed on the screw 110. The end of the screw 110 opposite to the nut 120 has a screw tip 131, which includes two pointed bodies 1311. The end of the nut 120 opposite to the screw 110 has a perforated groove 121.

[0039] The tension screw for treating lumbar spondylolysis provided in this embodiment includes a screw 110, a nut 120, and a thread 130. The screw tip 131 includes two pointed bodies 1311, and one end of the screw 110 has a perforated groove 121. The two pointed bodies 1311 of the screw tip 131 improve the penetration ability of the tension screw for treating lumbar spondylolysis, enabling it to just penetrate the pedicle cortex, reducing the risk of nerve damage and lower limb pain, and making the screw tightening process more convenient. The perforated groove 121 at one end of the screw 110 provides better holding force when tightening and removing the screw, effectively reducing the risk of stripping at the contact point and promoting the healing of lumbar spondylolysis.

[0040] In one feasible implementation, the plum blossom groove 121 includes a groove body 1211 and a plurality of groove petals 1212 connected to the groove body 1211. The plurality of groove petals 1212 are evenly arranged on the periphery of the groove body 1211, and the inner wall of each groove petal 1212 is arc-shaped.

[0041] In this technical solution, a plum blossom groove 121 is further provided. The plum blossom groove 121 includes a groove body 1211 and multiple groove segments 1212 connected to the groove body 1211. The inner wall of each groove segment 1212 is arc-shaped. Based on this, when the tension screw used to treat lumbar spondylolysis is tightened with a tool, there are more contact points between the tool and the tension screw used to treat lumbar spondylolysis, which can further reduce the risk of stripping at the contact points.

[0042] In one feasible embodiment, the length of the screw 110 is 32 mm to 40 mm; the thickness of the nut 120 is 2 mm to 3 mm; the coverage length of the thread 130 on the screw 110 is 12 mm to 20 mm; the diameter of the screw 110 is 2.5 mm to 3.5 mm; and the outer diameter of the thread 130 is 4 mm to 4.5 mm.

[0043] In this technical solution, structural parameters of the screw 110 and the thread 130 are further provided. By selecting the above parameters, the tension thread 130 can be fully wrapped on the opposite side, which can effectively improve the tension effect of the screw. When applying pressure to the lumbar isthmus, the new tension screw can provide sufficient tension, and it is more convenient and faster to operate the screw of this utility model with a screwdriver.

[0044] In one feasible embodiment, the length of the screw 110 is 38 mm; the thickness of the nut 120 is 2.5 mm; the coverage length of the thread 130 on the screw 110 is 15 mm; the diameter of the screw 110 is 3 mm; and the outer diameter of the thread 130 is 4.5 mm.

[0045] In this technical solution, specific structural parameters of the screw 110 and the thread 130 are further provided. By selecting the above parameters, the tension thread 130 can be fully wrapped on the opposite side, which can effectively improve the tension effect of the screw. When applying pressure to the lumbar isthmus, the new tension screw can provide sufficient tension, and it is more convenient and faster to operate the screw of this utility model with a screwdriver.

[0046] In one feasible implementation, the thread 130 is a double thread 130 with a pitch of 1 mm to 2 mm, a total number of 7 to 12 turns, triangular threads, a distal end inclination angle of 50° to 70°, and a proximal end inclination angle of 60° to 80°.

[0047] In this technical solution, specific parameters of thread 130 are further provided. Thread 130 is a double thread 130, which can effectively improve the tensile effect of the screw. When applying pressure to the isthmus of the lumbar spine, it can provide effective tensile force and also apply pressure to the isthmus.

[0048] In one feasible implementation, the pitch is 1.5 mm, the total number of turns is 10, the threads are triangular, the distal end is inclined at an angle of 50° to 60°, and the proximal end is inclined at an angle of 70°.

[0049] In this technical solution, specific parameters of thread 130 are further provided. Thread 130 is a double thread 130, which can effectively improve the tensile effect of the screw. When applying pressure to the isthmus of the lumbar spine, it can provide effective tensile force and also apply pressure to the isthmus.

[0050] In one feasible embodiment, a groove 1312 is formed between two adjacent tips 1311, and the depth of the groove 1312 is 0.46 mm. This design improves the penetration capability of the lag screw used to treat lumbar spondylolysis, enabling it to just penetrate the pedicle cortex, reducing the risk of nerve damage and lower limb pain, and making the screw tightening process more convenient.

[0051] The lag screw provided in this application for treating lumbar isthmus fracture involves the following steps during use: A translaminar lag screw is inserted into the affected vertebra. After dissecting the tissue surrounding the lower edge of the lamina, the scar tissue and soft tissue at the isthmus fracture ends are cleaned to expose the bone surface. Autologous bone is then implanted at the isthmus fracture ends, and the lag screw connects the fracture ends, applying pressure to the lumbar isthmus. The lag screw's lag thread 130 portion penetrates the contralateral cortex. The double-threaded 130 design provides higher holding force when applying pressure to the lumbar isthmus, allowing for a better fit to the local anatomical structure.

[0052] In this utility model, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "install," "connect," "join," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "join" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0053] In the description of this utility model, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0054] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0055] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A tension screw for treating a spondylolysis of a lumbar vertebra, characterized in that Comprising: a screw rod, a screw cap and a thread, the screw cap is arranged at one end of the screw rod, and the thread is arranged on the screw rod; wherein the end of the screw rod away from the screw cap is formed with a screw tip, and the screw tip comprises two tip bodies; wherein the end of the screw cap away from the screw rod is formed with a keyway.

2. The tension screw for treating a spondylolysis according to claim 1, characterized in that, The keyway comprises a groove body and a plurality of groove petals communicated with the groove body, and the plurality of groove petals are uniformly arranged on the circumferential side of the groove body, and the inner wall of each groove petal is arc-shaped.

3. The tension screw for treating lumbar spondylolysis according to claim 1, wherein: the length of the screw rod is 32mm to 40mm; the thickness of the screw cap is 2mm to 3mm; the covered length of the thread on the screw rod is 12mm to 20mm; the diameter of the screw rod is 2.5mm to 3.5mm; the outer diameter of the thread is 4mm to 4.5mm.

4. The tension screw for treating lumbar spondylolysis according to claim 3, wherein: the length of the screw rod is 38mm; the thickness of the screw cap is 2.5mm; the covered length of the thread on the screw rod is 15mm; the diameter of the screw rod is 3mm; the outer diameter of the thread is 4.5mm.

5. The tension screw for treating lumbar spondylolysis according to any one of claims 1 to 4, wherein: the thread is a double thread, the pitch is 1mm to 2mm, the total number of turns is 7 to 12 turns, the thread is triangular, the distal end inclination angle is 50° to 70°, and the proximal end inclination angle is 60° to 80°.

6. The tension screw for treating lumbar spondylolysis according to claim 5, wherein: the pitch is 1.5mm, the total number of turns is 10 turns, the thread is triangular, the distal end inclination angle is 50° to 60°, and the proximal end inclination angle is 70°.

7. The tension screw for treating lumbar spondylolysis according to claim 5, wherein: a groove is formed between the two adjacent tip bodies, and the depth of the groove is 0.46mm.

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