Short-tail coaxial screw for cervical vertebra surgery

Abstract

The utility model belongs to the field of medical instruments, and particularly relates to a short-tail coaxial screw for cervical vertebra surgery, which comprises a screw seat, a U-shaped groove is arranged on the screw seat, a boss is arranged in the U-shaped groove, the boss is clamped with a screw body, the screw body comprises a heightening column, a step is arranged on the heightening column, the step is clamped with the boss, the size of the step is larger than that of the boss, and the height of the heightening column is larger than that of the boss. The screw body further comprises a ball head, a screw neck and a bone thread, the bone thread is of a single-thread structure, the steps are arranged in a multi-step mode, the steps are gradually increased from the end close to the screw neck to the end away from the screw neck, and a titanium coating is sprayed on the surface of the bone thread. When the screw base and the screw body are assembled, the heightening column on the screw body is pressed into the screw base, the boss on the screw base and the step on the heightening column are clamped, the screw body cannot be disengaged, the connecting stability of the screw base and the screw body is improved, and the situation of early loosening of a product is avoided.

Description

Technical Field

[0001] The utility model belongs to the field of medical instruments, and in particular relates to a short-tail coaxial screw for cervical vertebra surgery. Background Art

[0002] Currently, most products on the market for posterior cervical fixation are universal pedicle screws, integrated fixed pedicle screws and other types. The structural design of universal pedicle screws on the market is mostly an assembly combination of screw seat, screw and locking rod screw.

[0003] The fixing principle of the universal pedicle screw is: when implanting orthopedic rod products, the rod is locked and pressed by the locking rod screw plug products, and the locking rod screw plug is pressed by force transmission. Due to the randomness of the screw seat and the implantation of the screw, the product may loosen early under multiple forces. Although the one-piece fixed pedicle screw has good mechanical properties, it cannot be rotated due to its fixed characteristics, which makes it inconvenient to operate during use. Summary of the invention

[0004] The utility model aims to solve the deficiencies of the prior art and provide a short-tail coaxial screw for cervical vertebra surgery which has a simple structure and can fix the screw in a threaded seat to avoid early loosening of the product.

[0005] The purpose of the utility model can be achieved through the following technical solutions: a short-tail coaxial screw for cervical spine surgery, which includes a screw seat, the screw seat is provided with a U-shaped groove, a boss is arranged in the U-shaped groove, and the boss is clamped with the screw body.

[0006] As a further optimization or improvement of the present solution, the nail body includes a heightening column, a step is provided on the heightening column, the step is engaged with the boss, and the size of the step is larger than the size of the boss.

[0007] As a further optimization or improvement of the present solution, the nail body further includes a ball head, a nail neck and a bone thread, and the bone thread is a single thread structure.

[0008] As a further optimization or improvement of this solution, a long waist groove is provided on the screw seat.

[0009] As a further optimization or improvement of the present solution, the steps are arranged in multiple steps, and the steps gradually increase from one end close to the nail neck to one end far from the nail neck.

[0010] As a further optimization or improvement of this solution, a titanium coating is sprayed on the surface of the bone threads.

[0011] Beneficial effects of the utility model:

[0012] (1) When assembling the screw seat and the nail body, press the heightening column on the nail body into the screw seat so that the boss on the screw seat and the step on the heightening column are locked, making it impossible for the nail body to fall out, thereby improving the connection stability between the screw seat and the nail body and avoiding early loosening of the product.

[0013] (2) The height of the nail body is increased by raising the column, thereby enhancing the structural strength of the nail body connection part and avoiding the situation where the top screw and orthopedic rod cannot be locked during the implantation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The utility model is further described below in conjunction with the accompanying drawings.

[0015] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0016] Figure 2 This is the structural exploded diagram of the screw seat and nail body.

[0017] Figure 3 It is a structural schematic diagram of the screw seat.

[0018] Figure 4 This is the structural connection diagram of the screw seat and the heightening column.

[0019] The markings in the figure are: 1. screw seat; 2. nail body; 21. ball head; 22. nail neck; 23. bone thread; 24. height increase column; 3. U-shaped groove; 4. long waist groove; 5. boss. DETAILED DESCRIPTION

[0020] 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 of 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.

[0021] See also Figure 1-Figure 4 A short-tail coaxial screw for cervical spine surgery includes a screw seat 1, wherein the screw seat 1 is provided with a U-shaped groove 3, a boss 5 is arranged in the U-shaped groove 3, and the boss 5 is clamped with the screw body 2.

[0022] It should be noted that the overall structure of the screw seat 1 is a hollow cylindrical shape, and a U-shaped groove 3 is milled on the upper half of the screw seat 1, wherein the U-shaped groove 3 is used to accommodate orthopedic implant orthopedic rod products, and a boss 5 is provided on the inner side of the U-shaped groove 3, wherein the boss 5 is used to cooperate with the heightening column 24 of the nail body 2 to limit the disengagement of the nail body 2. A ball hole is provided at the bottom of the screw seat 1, and the ball hole cooperates with the ball head 21 of the nail body 2.

[0023] See also Figure 3 , the screw seat 1 is provided with a long waist groove 4. It should be noted that the outer wall of the screw seat 1 has four long waist grooves 4, and the long waist grooves 4 are in the same direction as the U-shaped groove 3, wherein the long waist grooves 4 cooperate with the implantation instrument.

[0024] See also Figure 4 The nail body 2 includes a heightening column 24 , on which a step is provided. The step is engaged with the boss 5 , and the size of the step is larger than that of the boss 5 .

[0025] It should be noted that the nail is mainly composed of four parts: a ball head 21, a nail neck 22, a bone thread 23 and a heightening column 24. In this solution, the heightening column 24 extending upward from the ball head 21 is used to increase the height of the nail body 2, thereby strengthening this part of the structure and avoiding the situation where top screws and orthopedic rods cannot be locked during the implantation process.

[0026] See also Figure 2 The steps are arranged in multiple steps, and the steps gradually increase from the end close to the nail neck 22 to the end far away from the nail neck 22.

[0027] It should be noted that the step on the heightening column 24 gradually increases upward along the outer wall of the heightening column 24, and the size of the step is slightly larger than the size of the boss 5. During the assembly process, the step is pressed into the screw seat 1, and the boss 5 on the screw seat 1 clamps the nail body 2, preventing the nail body 2 from falling out.

[0028] See also Figure 2 The nail body 2 also includes a ball head 21, a nail neck 22 and a bone thread 23, and the bone thread 23 is a single thread structure.

[0029] The surface of the bone threads 23 is sprayed with a titanium coating.

[0030] It should be noted that the nail neck 22 is designed as a bare rod structure without other structural features, in order to improve the performance strength of the nail neck 22 and prevent the nail neck 22 from breaking during the implantation process. The bone thread 23 is designed as a single thread structure and the surface of the bone thread 23 is sprayed with a titanium coating. The nail tail (the first part to contact the bone) has a self-tapping groove structure for easy implantation into the human body.

[0031] The implementation principle of the utility model is: during surgery, before the screw seat 1 and the nail body 2 are implanted into the vertebral body, the heightening column 24 on the nail body 2 is pressed into the screw seat 1, so that the boss 5 on the screw seat 1 is stuck to the step on the heightening column 24, so that the nail body 2 cannot fall out, and then the screw seat 1 and the nail body 2 are implanted into the vertebral body, and the spine is fixed and reset by mechanical connection with the screw seat 1 and the nail body 2 by orthopedic rods, locking rod screws, etc. In this process, the heightening column 24 increases the height of the nail body 2, while strengthening this part of the structure, avoiding the situation that the top screw and orthopedic rod products cannot be locked during the implantation process, and providing temporary or short-term mechanical stability for maintaining the overall alignment of the spine.

[0032] It should be noted that the present invention is composed of a screw seat 1 and a nail body 2. The screw seat 1 is made of forged cobalt-chromium-molybdenum alloy, and the nail is made of titanium alloy (TC4). Most of the materials of products used for posterior cervical internal fixation on the market are titanium alloys. In this solution, the screw seat 1 is made of forged cobalt-chromium-molybdenum alloy, so that the mechanical properties of this solution are better than other posterior cervical internal fixation products made of titanium alloy.

[0033] The advantages of this solution are: first, compared with the universal pedicle screw, it has stronger support and better reduction effect; second, this solution is consistent with the one-piece fixation screw in terms of stability, and is easier to implant than the one-piece fixation screw; third, the product surface of this solution is covered with a titanium coating, and the porous coating structure is beneficial to bone growth.

[0034] The above shows and describes the basic principle, main features and advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments, and the above embodiments and descriptions are only for explaining the principle of the utility model. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, and these changes and improvements fall within the scope of the utility model to be protected.

Claims

1. A short-tail coaxial screw for cervical spine surgery, characterized in that: It comprises a screw seat (1), wherein the screw seat (1) is provided with a U-shaped groove (3), a boss (5) is arranged in the U-shaped groove (3), and the boss (5) is clamped with the nail body (2); The nail body (2) comprises a height-enhancing column (24), on which a step is provided, the step being engaged with the boss (5), and the size of the step being larger than the size of the boss (5).

2. A short-tail coaxial screw for cervical spine surgery according to claim 1, characterized in that: The nail body (2) further comprises a ball head (21), a nail neck (22) and a bone thread (23), and the bone thread (23) is a single thread structure.

3. A short-tail coaxial screw for cervical spine surgery according to claim 1, characterized in that: The screw seat (1) is provided with a long waist groove (4).

4. A short-tail coaxial screw for cervical spine surgery according to claim 1, characterized in that: The steps are arranged in multiple steps, and the steps gradually increase from an end close to the nail neck (22) to an end far from the nail neck (22).

5. A short-tail coaxial screw for cervical spine surgery according to claim 2, characterized in that: The surface of the bone thread (23) is sprayed with a titanium coating.

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