A spondylolisthesis correction device

Abstract

The utility model discloses a lumbar spondylolisthesis correction device, including fixed screw, lifting screw and connecting rod, two fixed screws are equipped with two sides of lifting screw, and two fixed screws all are equipped with the nut on the upper end, the both sides of nut all are equipped with the opening of connecting rod's putting, and the screw rod for the screwing of nut inner is used for the compression connecting rod, and the opening of two fixed screws can insert the limiting rod, and the both ends of limiting rod all are equipped with the hook on the thread of screw rod's outside. The fixed screw of this lumbar spondylolisthesis correction device is fixed in the vertebral body of the upper and lower of spondylolisthesis vertebral body, and the lifting screw is fixed in spondylolisthesis vertebral body, and the pulling force is exerted to the lifting screw and drives spondylolisthesis vertebral body to reset, and the screw rod is screwed down and fixes the connecting rod, and the limiting rod is loaded into the limiting rod and makes the hook of the both ends of limiting rod hook on the thread of screw rod's outside, makes limiting rod, screw rod, fixed screw and connecting rod form closed loop, and the connecting rod that limits to bend outward continues to outwardly occur deformation recovery, avoids the overcorrection of spondylolisthesis vertebral body.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, specifically to a lumbar spondylolisthesis correction device. Background Technology

[0002] The correction of lumbar spondylolisthesis usually involves fixing the vertebral body above and below the slipped vertebral body with a fixation screw and fixing the traction screw to the slipped vertebral body. The fixation screw and the traction screw are fixed together by a connecting rod. By applying a pulling force to the traction screw, the slipped vertebral body is reduced in position.

[0003] For example, Chinese utility model patent application number 202122066623.7 discloses a corrective traction reduction device for lumbar spondylolisthesis reduction, including two fixing screws, a lifting screw, and a connecting rod. The two fixing screws are symmetrically arranged on both sides of the lifting screw. A first connecting rod is provided above the fixing screws. A first threaded post is fixedly connected to the top of the fixing screws. The first threaded post is internally connected to the bottom end of the first connecting rod through threads. In actual use, the bending angle of the connecting rod in this corrective traction reduction device cannot be controlled. During the process of restoring deformation, the bent connecting rod may overcorrect the slipped vertebral body, thereby causing the slipped vertebral body to slip backward. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the technical problem to be solved by this utility model is to provide a lumbar spondylolisthesis correction device with accurate correction and positioning.

[0005] Therefore, this utility model is implemented using the following technical solution:

[0006] A lumbar spondylolisthesis correction device includes two fixing screws, two lifting screws, and two connecting rods. The device is characterized in that: each of the two fixing screws has a nut at its upper end, and each of the nuts has an opening on both sides for inserting the connecting rod. A screw rod for pressing the connecting rod can be screwed into the nut. A limiting rod can be inserted into the opening of the two fixing screws. Both ends of the limiting rod have hooks that can hook onto the outer threads of the screw rod.

[0007] Furthermore, the limiting rod includes an upper rod and a lower rod. The lower rod is provided with a strip-shaped through hole, and the upper rod is screwed with a bolt that can pass through the strip-shaped through hole. The upper part of the bolt is provided with a pressing part that can press against the end face of the lower rod around the strip-shaped through hole.

[0008] Furthermore, the outer ends of the screw and bolt are provided with internal hexagonal countersunk holes, and the outer ring of the screw is provided with a slot for inserting a hook.

[0009] Furthermore, a pressure block is provided between the screw and the connecting rod, the upper end face of the pressure block abuts against the lower end face of the screw, and the lower end of the pressure block is provided with an arc-shaped opening groove for inserting the connecting rod.

[0010] Furthermore, the arc-shaped opening groove is provided with several spikes, and the pressure block and spikes are made of titanium alloy.

[0011] After adopting the above technical solution, two fixing screws are fixed to the vertebral bodies above and below the slipped vertebral body, and a lifting screw is fixed to the slipped vertebral body. By applying a pulling force to the lifting screw, the slipped vertebral body is driven to reposition. Then, the connecting rod is fixed by tightening the screw. At this time, the connecting rod still has an outward bending arc and still has a force to restore deformation, providing a pulling force to the lifting screw. Finally, the limiting rod is installed so that the hooks at both ends of the limiting rod hook onto the threads on the outside of the screw, so that the limiting rod, screw, fixing screw and connecting rod form a closed loop, restricting the outward bending connecting rod from continuing to deform outward, thereby completing the positioning of the connecting rod and the lifting screw, and thus keeping the slipped vertebral body in the position after repositioning, avoiding overcorrection of the slipped vertebral body. Attached Figure Description

[0012] The present invention includes the following figures:

[0013] Figure 1 This is a schematic diagram of the structure of this utility model;

[0014] Figure 2 for Figure 1 A schematic diagram showing the structure of the nut and the limiting rod cut in half.

[0015] Figure 3 This is a partial cross-sectional view of the fixing screw in this utility model;

[0016] Figure 4 This is a schematic diagram of the structure of the pressure block in this utility model.

[0017] Reference numerals: 1. Fixing screw; 2. Lifting screw; 3. Connecting rod; 4. Nut; 5. Opening; 6. Screw; 7. Limiting rod; 8. Hook; 9. Upper rod; 10. Lower rod; 11. Strip-shaped through hole; 12. Bolt; 13. Clamping part; 14. Socket headstock countersunk hole; 15. Slot; 16. Arc-shaped opening slot; 17. Spike; 18. Pressure block. Detailed Implementation

[0018] To further illustrate the technical means and effects adopted by this utility model in order to achieve the intended utility model purpose, the following detailed description of the specific implementation methods, structure, features and effects of this utility model is provided in conjunction with the accompanying drawings and preferred embodiments.

[0019] Referring to the above-mentioned figures, the lumbar spondylolisthesis correction device provided by this utility model includes a fixing screw 1, a lifting screw 2, and a connecting rod 3. There are two fixing screws 1, located on both sides of the lifting screw 2. The device is characterized in that: each of the two fixing screws 1 has a nut 4 at its upper end, and each nut 4 has an opening 5 on both sides for inserting the connecting rod 3. A screw rod 6 for pressing the connecting rod 3 can be screwed into the nut 4. A limiting rod 7 can be inserted into the opening 5 of the two fixing screws 1. Both ends of the limiting rod 7 have hooks 8 that can hook onto the outer threads of the screw rod 6. The limiting rod 7 includes an upper rod 9 and a lower rod 10. The lower rod 10 has... A strip-shaped through hole 11 is provided. A bolt 12, which can pass through the strip-shaped through hole 11, is screwed onto the upper rod 9. The upper part of the bolt 12 is provided with a clamping part 13 that can press against the end face of the lower rod 10 around the strip-shaped through hole 11. The outer ends of the screw 6 and the bolt 12 are provided with internal hexagon countersunk holes 14. The outer ring of the screw 6 is provided with a slot 15 for inserting a hook 8. A pressure block 18 is provided between the screw 6 and the connecting rod 3. The upper end face of the pressure block 18 abuts against the lower end face of the screw 6. The lower end of the pressure block 18 is provided with an arc-shaped opening 5 groove for inserting the connecting rod 3. Several spikes 17 are provided in the arc-shaped opening 5 groove. The pressure block 18 and the spikes 17 are made of titanium alloy.

[0020] In this embodiment, two fixing screws 1 are fixed to the vertebral bodies above and below the slipped vertebral body, and a lifting screw 2 is fixed to the slipped vertebral body. By applying a pulling force to the lifting screw 2, the slipped vertebral body is repositioned. Then, the connecting rod 3 is fixed by tightening the screw 6. At this time, the connecting rod 3 still has an outward bending arc and still has a force to restore its deformation, providing a pulling force to the lifting screw 2. Finally, the limiting rod 7 is installed, so that the hooks 8 at both ends of the limiting rod 7 hook onto the threads on the outside of the screw 6, so that the limiting rod 7, screw 6, fixing screw 1 and connecting rod 3 form a closed loop, restricting the outward bending of the connecting rod 3 from continuing to deform outward, thereby completing the positioning of the connecting rod 3 and the lifting screw 2, and thus keeping the slipped vertebral body in the repositioned position, avoiding overcorrection of the slipped vertebral body; the limiting rod 7 consists of an upper rod 9, a lower rod 10 and a bolt 12, and the bolt 12 is not tightened. The upper rod 9 and lower rod 10 can move relative to each other. After the hook 8 hooks the thread, the positions of the upper rod 9 and lower rod 10 are adjusted, and then the bolt 12 is tightened to fix the upper rod 9 and lower rod 10. This is applicable to two fixing screws 1 with different spacing, making it more versatile. The universal hexagon countersunk hole 14 facilitates the tightening and loosening of the screw 6 and bolt 12. The slot 15 is set in conjunction with the hook 8, which not only makes the structure of the limit rod 7 and screw 6 more stable, but also prevents the screw 6 from loosening inside the body, ensuring accurate positioning. The arc opening 5 groove of the pressure block 18 has a larger contact area with the connecting rod 3, and the upper end face of the pressure block 18 is pressed by the screw 6, making the structure of the screw 6, pressure block 18 and connecting rod 3 more stable and firm, and preventing relative displacement between the connecting rod 3 and screw 6. Several titanium alloy spikes 17 can firmly abut against the connecting rod 3, increasing structural stability.

[0021] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A lumbar spondylolisthesis correction device, comprising a fixing screw, a lifting screw, and a connecting rod, wherein there are two fixing screws, and the two fixing screws are located on both sides of the lifting screw, characterized in that: Both fixing screws have nuts at their upper ends, and openings on both sides of the nuts are for inserting a connecting rod. A screw rod for pressing the connecting rod can be screwed into the nut. A limiting rod can be inserted into the openings of the two fixing screws, and both ends of the limiting rod are provided with hooks that can hook onto the outer threads of the screw rod.

2. The lumbar spondylolisthesis correction device according to claim 1, characterized in that: The limiting rod includes an upper rod and a lower rod. The lower rod has a strip-shaped through hole, and the upper rod is screwed with a bolt that can pass through the strip-shaped through hole. The upper part of the bolt has a pressing part that can press against the end face of the lower rod around the strip-shaped through hole.

3. The lumbar spondylolisthesis correction device according to claim 2, characterized in that: The outer ends of the screw and bolt are provided with internal hexagonal countersunk holes, and the outer ring of the screw is provided with a slot for inserting a hook.

4. A lumbar spondylolisthesis correction device according to claim 1, 2, or 3, characterized in that: A pressure block is provided between the screw and the connecting rod. The upper end face of the pressure block abuts against the lower end face of the screw, and the lower end of the pressure block is provided with an arc-shaped opening groove for inserting the connecting rod.

5. The lumbar spondylolisthesis correction device according to claim 4, characterized in that: The arc-shaped opening groove is provided with several spikes, and the pressure block and spikes are made of titanium alloy.

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