Pedicle screw capable of axially and universally rotating

Abstract

The utility model belongs to the technical field of spine correction instruments and equipment, and particularly relates to a pedicle screw capable of axially and universally rotating. A pedicle screw capable of axially and universally rotating comprises a screw seat and a universal screw, the screw seat comprises a screw fixing seat and two side ear crowns, and the two side ear crowns are symmetrically arranged at the top of the screw fixing seat; a screw through hole is formed in the screw fixing seat, and a universal screw is arranged in the screw through hole; the universal screw comprises a screw ball head and a screw rod, the screw ball head is fixedly connected with the screw rod, the screw ball head is located in the screw fixing seat, and the screw rod penetrates through the screw through hole; the upper half portion of the screw ball head is a limiting circular truncated cone, a limiting concave ring is arranged at the position of the limiting circular truncated cone, and a plurality of punching and riveting notches are formed in the outer side wall of the screw fixing base.

Description

Technical Field

[0001] The utility model belongs to the technical field of spinal correction equipment, and in particular relates to a pedicle screw capable of axial universal rotation. Background Art

[0002] The pedicle screw is a fixation device used in spinal surgery, mainly for the stability and correction of the thoracolumbar spine. It enters the vertebral body through the pedicle and uses the anatomical structure of the pedicle to achieve fixation of the spine. The development of pedicle screw technology has gone through several stages, including the pedicle screw developed by Roy-Camille in 1961. Pedicle screw systems are mainly divided into two categories: screw-plate system and screw-rod system. The steps of pedicle screw surgery include clear exposure, accurate positioning, directional depth, opening, straight round head probe insertion, C-arm positioning and screw placement. The approaches for pedicle screw surgery include the traditional posterior median approach and the paraspinal muscle space approach, the latter of which is particularly suitable for the removal and revision of spinal internal fixation.

[0003] During pedicle screw surgery, the multifidus muscle is an important structure that plays a key role in the stability of the spine, especially dynamic stability. Pedicle screw fixation has become a major way to maintain thoracic stability after thoracic surgery, and a variety of technologies have been used in clinical practice, including the use of C-arm machines, CT three-dimensional reconstruction assistance, and computer navigation.

[0004] Accurate placement of the pedicle screw system is the key to a successful operation. The focus of clinical research is how to improve the accuracy of screw placement and reduce secondary screw placement. The steps of pedicle screw placement include determining the screw insertion point, grasping the horizontal plane angle (TSA) and sagittal plane angle (SSA), and having certain requirements for the screw insertion depth and screw length. The pedicle screw (PS) is one of the strongest structures of the spine and can withstand lateral bending stress, rotational stress, and flexion-extension stress. Pedicle screw fixation is an important part of spinal surgery. It helps maintain the stability of the thoracic and lumbar spine through the precise placement of pedicle screws.

[0005] When using the pedicle screw system to correct the spine and other parts, sometimes a pedicle screw that can be adjusted in three dimensions is needed to cope with different fixed positions; sometimes a pedicle screw that can only rotate axially is also needed. The main application scenarios of pedicle screws that can only rotate axially are: spinal slippage, fracture or dislocation, degenerative disc lesions, scoliosis and other diseases, which lead to the loss of biomechanical stability of the spine and the inability to maintain normal height. It is necessary to implant pedicle screws in the adjacent vertebrae on both sides of the injured vertebra, install orthopedic rods and screw plugs, and then use the pedicle screws as a fulcrum to use distraction pliers and (or) pressure pliers to distract and pressurize to restore the normal sequence and height of the spine and maintain the biomechanical stability of the spine. During the distraction and pressurization process, the screw seat and universal screw of the conventional universal pedicle screw can move 360°, and need to be finally locked before they can be completely fixed, resulting in insufficient distraction and pressure, so that the vertebral body cannot be restored to the ideal height. The use of uniaxial pedicles can improve this problem. However, uniaxial pedicle screws are an integrated structure. Due to individual differences in patients and vertebral structure, it is difficult to ensure that the screw openings are in the same straight line during the installation of the implant, making it difficult to install the orthopedic rod. If the direction of the screw seat opening groove is adjusted by adjusting the screw implant depth, there is a risk of the pedicle screw penetrating the vertebral body or insufficient screw holding force.

[0006] Therefore, pedicle screws that can only rotate axially have a relatively important use in related surgeries. Existing pedicle screws that can only rotate axially usually use the method of stamping the tail of the screw to complete the riveting between the screw and the screw seat. This connection method often causes the screw to be damaged by stamping, and there are many irregular parts such as burrs, which may cause inflammation to the patient when inserted into the human body.

[0007] In order to solve the drawbacks of the method of punching the screw tail, the utility model hopes to provide a pedicle screw that can be axially universally rotated. Utility Model Content

[0008] The utility model aims to provide a pedicle screw capable of axial universal rotation, so as to solve the problems raised in the above-mentioned background technology.

[0009] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0010] A pedicle screw capable of axial universal rotation comprises a screw seat and a universal screw; the screw seat comprises a screw fixing seat and two side ear crowns, the two side ear crowns are symmetrically arranged on the top of the screw fixing seat; a screw through hole is arranged in the screw fixing seat, and a universal screw is arranged in the screw through hole; the universal screw comprises a screw ball head and a screw rod, the screw ball head and the screw rod are fixedly connected, the screw ball head is located in the screw fixing seat, and the screw rod passes through the screw through hole; the upper half of the screw ball head is a limiting truncated cone, a limiting recessed ring is arranged at the limiting truncated cone, and a plurality of riveting notches are arranged at the outer side wall of the screw fixing seat.

[0011] Preferably, thread grooves are provided on the inner walls of the two side ear crowns.

[0012] Preferably, connecting notches are provided on the outer walls of the two side ear crowns.

[0013] Preferably, the top of the screw ball head is a hexalobular socket.

[0014] Preferably, the surface of the screw is provided with threads, and the number of threads in the upper half of the screw is greater than the number of threads in the lower half of the screw.

[0015] Preferably, the lower half of the screw ball head is a curved hemisphere, and correspondingly, the inner wall of the screw fixing seat is a curved concave inner wall.

[0016] Compared with the prior art, the beneficial effects of the utility model are:

[0017] (1) The utility model provides a pedicle screw capable of axial universal rotation, wherein the upper half of the ball head of the screw is a limiting cone, a limiting concave ring is provided at the limiting cone, and a plurality of rivet notches are provided at the outer wall of the screw fixing seat corresponding to the position of the limiting concave ring; when manufacturing the product, a punching drill is used to punch the rivet notches, so that the rivet notches are further concave inward, and the bottom of the deformed rivet notches is sunken into the limiting concave ring, so as to limit the connection of the universal screw; this process does not produce excessive deformation, and will not cause the product to be damaged during the manufacturing process, and the integrity of the product is better;

[0018] (2) The utility model provides a pedicle screw capable of axial universal rotation, and a limiting concave ring is used at the limiting cone, so that the universal screw can rotate independently of the screw seat during the process of inserting the product into the spine, thereby reducing the situation where the screw seat rotates with the rotation of the universal screw, which may damage the tissue near the surgical site;

[0019] (3) The utility model provides a pedicle screw that can be universally rotated axially. The screw seat and the universal screw are an integrated structure, which can avoid insufficient distraction and pressure during surgery. At the same time, the universal screw can rotate freely along the axial direction of the screw seat. Rotating the screw seat during surgery can make the orthopedic rod easily installed, avoiding the pedicle screw from penetrating the vertebral body or insufficient screw holding force. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of the utility model;

[0021] Figure 2 It is the assembly drawing of the utility model;

[0022] Figure 3 This is a cross-sectional view of the utility model before riveting;

[0023] Figure 4 This is a cross-sectional view of the utility model after punching and riveting;

[0024] In the figure: 1. nail seat; 2. universal screw; 3. screw fixing seat; 4. side ear crown; 5. threaded groove; 6. connecting notch; 7. screw through hole; 9. screw ball head; 10. screw rod; 11. limiting cone; 12. limiting recessed ring; 13. punching rivet notch; 14. thread; 15. plum blossom slot. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0026] A pedicle screw capable of axial universal rotation comprises a screw base 1 and a universal screw 2. The screw base 1 comprises a screw fixing base 3 and two side ear crowns 4, and the two side ear crowns 4 are symmetrically arranged on the top of the screw fixing base 3. An orthopedic rod mounting groove is formed between the two side ear crowns 4. In order to achieve the fixation of the orthopedic rod, a thread groove 5 is provided on the inner wall of the two side ear crowns 4. At the same time, a connecting notch 6 is provided on the outer wall of the two side ear crowns 4, which is mainly used for connecting the screw base 1 with other equipment.

[0027] A screw through hole 7 is provided in the screw fixing seat 3 of the nail seat 1, and a universal screw 2 is provided in the screw through hole 7. The universal screw 7 includes a screw ball head 9 and a screw rod 10, and the screw ball head 9 and the screw rod 10 are fixedly connected. The screw ball head 9 is located in the screw fixing seat 3, and the screw rod 10 passes through the screw through hole 7. In order to assemble the nail seat 1 and the universal screw 2, the upper half of the screw ball head 9 is a limiting cone 11, and the limiting cone 11 is provided with a limiting recessed ring 12. Corresponding to the limiting recessed ring 12, two rivet notches 13 are provided on the outer wall of the screw fixing seat 3. During the assembly process, the universal screw 2 is placed into the nail seat 1, and the punching head is further aligned with the two rivet notches 13 for punching. When the bottom of the rivet notch 13 is deformed and just embedded in the limiting recessed ring 12, the assembly of the universal screw 2 and the nail seat 1 is completed. And due to the design of the limiting recessed ring 12, the universal screw 2 and the nail seat 1 can be relatively independent, and the universal screw 2 can rotate around the axis. In order to increase the connection stability between the nail seat 1 and the universal screw 2, the lower half of the screw ball head 9 is a curved hemisphere, and correspondingly, the inner wall of the screw fixing seat 3 is a curved concave inner wall. Threads 14 are provided on the surface of the screw rod 10. The setting of the threads 14 facilitates the universal screw 2 to be screwed into the target position. The number of threads 14 in the upper half of the screw rod 10 is greater than the number of threads 14 in the lower half of the screw rod 10. In order to facilitate the screwing of the universal screw 2, a hexalobular socket 15 is provided on the top of the screw ball head 9.

[0028] During the assembly process, the universal screw 2 is inserted from the top of the screw seat 1 until the lower half of the spherical surface of the universal screw 2 abuts against the screw fixing seat 3. Further, the assembler punches the punching rivet notch 13 with the help of a punching head, so that the bottom of the punching rivet notch 13 is deformed inwardly, and the deformed part is just embedded in the limiting recessed ring 12, and the assembly is completed. After the assembly is completed, the universal screw 2 and the screw seat 1 can rotate relatively independently, which is convenient for screwing the universal screw 2 into the specified vertebra when in use, while the screw seat 1 can remain stationary, avoiding damage to the surrounding wound tissue when the screw seat 1 rotates.

[0029] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A pedicle screw capable of axial universal rotation, characterized in that: It includes a nail seat and a universal screw; the nail seat includes a screw fixing seat and two side ear crowns, and the two side ear crowns are symmetrically arranged on the top of the screw fixing seat; a screw through hole is provided in the screw fixing seat, and a universal screw is provided in the screw through hole; the universal screw includes a screw ball head and a screw rod, and the screw ball head and the screw rod are fixedly connected, the screw ball head is located in the screw fixing seat, and the screw rod passes through the screw through hole; the upper half of the screw ball head is a limiting cone, and a limiting recessed ring is provided at the limiting cone, and a plurality of rivet notches are provided at the outer side wall of the screw fixing seat.

2. The axially universally rotatable pedicle screw according to claim 1, characterized in that: The inner walls of the two side ear crowns are both provided with thread grooves.

3. The axially universally rotatable pedicle screw according to claim 1, characterized in that: A connecting notch is arranged on the outer walls of the two side ear crowns.

4. The axially universally rotatable pedicle screw according to claim 1, characterized in that: The top of the screw ball head is a hexalobular socket.

5. The axially universally rotatable pedicle screw according to claim 1, characterized in that: The surface of the screw is provided with threads, and the number of threads in the upper half of the screw is greater than the number of threads in the lower half of the screw.

6. The axially universally rotatable pedicle screw according to claim 1, characterized in that: The lower half of the screw ball head is a curved hemisphere, and correspondingly, the inner wall of the screw fixing seat is a curved concave inner wall.

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