CN205268261U - Chest lumbar vertebrae way of escape fine motion fixing system - Google Patents

Abstract

The utility model relates to the field of orthopedic medical devices, in particular to a thoracolumbar posterior micro-motion fixation system for fixing the thoracolumbar spine when the thoracolumbar spine is diseased or damaged. The system includes two micro-movement pedicle screws, a titanium alloy connecting rod used to connect the two micro-movement pedicle screws, and a locking top for locking and fixing the titanium alloy connecting rod and micro-moving pedicle screws. Silk. The micro-movement pedicle screw is composed of two parts: a ball-head screw and a screw base. The ball-head screw is riveted with the screw base. The seat rotates slightly in a limited direction, and the front end of the nail seat catches the front part of the ball head of the ball stud. The micro-motion fixation system for the posterior thoracolumbar spine of the utility model fully considers the anatomical characteristics of the Chinese people. All design parameters are directly obtained from the anatomical data of the Chinese spine.

Description

Thoracolumbar posterior micro-movement fixation system

technical field

The utility model relates to the field of orthopedic medical devices, in particular to a thoracolumbar posterior micro-motion fixation system for fixing the thoracolumbar spine when the thoracolumbar spine is diseased or damaged.

Background technique

Lumbar fusion surgery is a general surgery for the treatment of lumbar instability caused by various diseases such as joint degeneration and intervertebral disc herniation. The key to the operation is to implant internal fixation devices to ensure the stability of the diseased lumbar spine, thereby giving the necessary conditions for bone graft fusion . The internal fixation device used is a strong system. After implantation in the lumbar spine, the mobility of the implanted segment will be excessively restricted, resulting in degeneration of adjacent segments and unreliable or even failure of bone graft fusion. At the same time, it may also be caused by internal stress If the concentration is too large, the system will fail, and phenomena such as looseness and nail removal will occur.

In this case, the demand for micro-movement internal fixation system arises at the historic moment. In the last 30 years, scholars from all over the world have been continuously researching micro-movement internal fixation systems, but so far, there are not many micro-motion internal fixation systems that are more mature and applied to the market. There are two main representatives, namely the Dynesys system and Graf ligament system. However, many scholars have found that both the Dynesys system and the Graf ligament system have serious defects. Therefore, in order to meet the needs of the market, it is necessary to design a simple and reliable posterior thoracolumbar micro-motion fixation system based on strong fixation.

Utility model content

Aiming at the defects of existing products, the utility model provides a thoracolumbar posterior fretting fixation system with simple and reliable structure, superior mechanical properties, convenient use, suitable for lumbar degeneration or recovery period of fusion surgery, and good stability.

The technical scheme of the utility model is:

A thoracolumbar posterior micro-movement fixation system, the system includes two micro-movement pedicle screws, a titanium alloy connecting rod for connecting the two micro-movement pedicle screws, and a titanium alloy connecting rod for locking and fixing And the locking set screw of the micro-motion pedicle screw.

In the posterior thoracolumbar micro-movement fixation system, the micro-movement pedicle screw is composed of a ball-head screw and a screw seat, the ball-head screw is riveted with the screw seat, the ball-head screw is fixed through the nail seat, and the nail seat and the ball The head nail forms a rotation range, so that the ball stud rotates slightly in a limited direction in the nail seat, and the front end of the nail seat catches the ball head front of the ball stud.

In the aforementioned thoracolumbar posterior micro-motion fixation system, the rotation range of the ball screw is controlled at -15 to 15 degrees.

In the aforementioned thoracolumbar posterior micro-motion fixation system, a pair of parallel planes are ground in the direction of riveting the ball-head nail with the nail seat, so that the ball-head nail and the nail seat are firmly riveted.

In the posterior thoracolumbar micro-movement fixation system, there is a U-shaped groove at the rear of the screw seat, and the micro-movement pedicle screw is fixedly connected to the titanium alloy connecting rod through the U-shaped groove, and the micro-movement pedicle screw is connected to the titanium alloy. The rods are in cylindrical contact.

In the aforementioned thoracolumbar posterior micro-movement fixation system, the rear part of the nail base is provided with an internal thread part, and the internal thread part is equipped with a locking screw, and the titanium alloy connecting rod is fixed by the locking screw.

In the aforementioned thoracolumbar posterior micro-movement fixation system, the front end of the nail seat has two slopes in the direction of the micro-movement of the ball-head screw.

In the aforementioned thoracolumbar posterior micro-motion fixation system, the ball-head screw and the nail seat are an assembly, and the two cannot be disassembled.

The thoracolumbar posterior micro-movement fixation system adopts micro-movement pedicle screws made of Ti-6Al-4V, titanium alloy connecting rods and locking jackscrews.

Compared with the prior art, the utility model has the following beneficial effects:

1. The thoracolumbar posterior fretting fixation system provided by the utility model is composed of fretting pedicle screws, titanium alloy connecting rods connected with fretting pedicle screws, and locking jackscrews. The locking jackscrews are used to fix titanium The alloy connecting rod has simple structure and high reliability.

2. The micro-movement pedicle screw of the present invention is composed of a ball-head screw and a screw base. The ball-head screw is fixed to the screw base through a riveting process. The ball-head screw can swing slightly in the screw base along the designated direction centered on the riveting point. , The ball head screw can control the swing angle, between -15 and 15 degrees, which can meet the normal activities of the lumbar spine fixed segment under flexion and extension conditions, and promote the recovery of the diseased lumbar spine.

3. The micro-movement fixation system of the utility model inherits the advantages of the strong fixation system, and realizes micro-movement under the premise of satisfying a good fixation effect. This feature has not been used clinically at present.

4. The fretting fixation system of the utility model has superior mechanical properties and good biocompatibility with human tissues.

5. The utility model conforms to the principle of human spine movement, and helps to restore the normal function of the spine.

Description of drawings

Fig. 1 is a schematic structural diagram of a posterior thoracolumbar micro-movement fixation system according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of a titanium alloy connecting rod of a posterior thoracolumbar micro-motion fixation system according to an embodiment of the present invention.

Fig. 3(a) - Fig. 3(b) are schematic diagrams of the locking jackscrew of the thoracolumbar posterior micro-movement fixation system according to an embodiment of the present invention. Wherein, Fig. 3(a) is a top view; Fig. 3(b) is a main view.

Fig. 4(a) - Fig. 4(g) are schematic diagrams of micro-motion pedicle screws of the posterior thoracolumbar micro-motion fixation system according to an embodiment of the present invention. Among them, Figure 4(a) is the overall structural diagram of the micro-movement pedicle screw; Figure 4(b) is the front view of the ball screw; Figure 4(c) is the side view of the ball screw; Figure 4(d) is the screw seat Top view; Figure 4(e) is a front view of the nail base; Figure 4(f) is a bottom view of the nail base; Figure 4(g) is a perspective view of the nail base.

In the figure, 1. Titanium alloy connecting rod; 2. Micro-movement pedicle screw; 3. Locking top wire; 4. Nail seat; 5. Ball head nail; 6. U-shaped groove; 7. Internal thread part; 8 , External thread part; 9 ball head; 10 closing; 11 bevel.

detailed description

Below, the utility model is further elaborated in detail in conjunction with the accompanying drawings.

Referring to Fig. 1, Fig. 2, Fig. 3(a)-Fig. 3(b), the thoracolumbar posterior fretting fixation system of the utility model includes two pedicle screws 2 which are fretting, and one of which connects two fretting vertebrae. The titanium alloy connecting rod 1 used for the pedicle screw 2 and the locking jackscrew 3 used for locking and fixing the titanium alloy connecting rod 1 and the micro-movement pedicle screw 2 .

As shown in Fig. 4(a), Fig. 4(b) and Fig. 4(c), the micro-movement pedicle screw 2 is composed of two parts, the ball-head screw 5 and the screw base 4, and the ball-head screw 5 and the screw base 4 are riveted together. As a whole, the ball stud 5 can rotate slightly in a limited direction in the nail seat 4, and the closing opening 10 at the front end of the nail seat 4 blocks the front part of the ball head 9 of the ball stud 5, preventing the ball stud 5 from being pulled out in the body. Simple and reliable. The external thread portion 8 of the micro-movement pedicle screw 2 is designed to be tapered (the taper range is 1 to 3 degrees), which can effectively improve the strength of the root of the micro-motion pedicle screw 2, and the root of the micro-motion pedicle screw 2 is always It is the part where the stress of the whole system is concentrated, and this design can reduce the risk of fracture of the micro-movement pedicle screw 2 from the root.

As shown in Fig. 4(b) and Fig. 4(c), a pair of parallel planes are ground in the riveting direction of the ball stud 5 and the nail seat 4, which can improve the riveting firmness of the ball stud 5 and the nail seat 4.

As shown in Fig. 4(a), Fig. 4(d), Fig. 4(e), Fig. 4(f), and Fig. 4(g), there is a U-shaped groove 6 at the rear of the screw seat 4, and the pedicle is slightly moved The screw 2 is fixedly connected to the titanium alloy connecting rod 1 through the U-shaped groove 6, and the fretting pedicle screw 2 and the titanium alloy connecting rod 1 are in cylindrical contact, ensuring firmness and reliability. The rear portion of the nail seat 4 is provided with an internal thread portion 7 for screwing in the locking jackscrew 3 to fix the titanium alloy connecting rod 1 in the U-shaped groove 6 by the locking jackscrew 3 . The ball stud 5 is loaded into from the nail holder 4 rear end, and the front end closing 10 of the nail holder 4 has two bevels 11 in the fretting direction (rotational direction) of the ball stud 5 to control the fretting angle of the ball stud 5. According to the normal movement angle between the lumbar segments of the human body, the micro-motion angle is controlled between -15 and 15 degrees (that is, the left and right rotation angle after normal installation).

Among them, the ball-head nail 5 and the nail seat 4 of the utility model are fixed by riveting, which not only provides a certain fixing effect on the ball-head nail 5, but also forms a rotation width, realizes the micro-movement of the ball-head nail 5 in the body, and fixes the lumbar spine. Segments can have a slight range of flexion and extension, changing the complete limitation of rigidly fixed lumbar segments.

When implanting the thoracolumbar posterior micro-motion fixation system, first determine the diseased segment of the patient's spine, insert micro-motion pedicle screws 2 according to requirements, and then press the titanium alloy connecting rod 1 into the U-shaped groove 6, Finally screw in the locking jackscrew 3, and the implantation process is safe and fast.

The micro-movement fixation system of the utility model can effectively improve the stress state of the implanted device in the body, reduce stress concentration, reduce stress shielding, and provide proper flexion and extension activities for the fixed segment. The simulation analysis technology predicts that under the physiological load of the human body, the stress level of the implanted device is lower than that of the rigid fixation.

The results of the examples show that the thoracolumbar posterior micro-movement fixation system of the present utility model aims at the postoperative complications of the current mainstream strong fixation system, combined with the relevant theories of human biomechanics, it is proposed from the perspective of mechanics to reconstruct the stability of the human lumbar spine. solution. The system fully considers the anatomical characteristics of the Chinese people, and all the design parameters are directly derived from the anatomical data of the Chinese spine, which can meet the needs of thoracolumbar internal fixation surgery, and the fixation and recovery effects are good.

Claims (9)

1. A thoracolumbar posterior micro-movement fixation system, characterized in that the system comprises two micro-movement pedicle screws, a titanium alloy connecting rod connected to the two micro-movement pedicle screws and a locking rod for locking Tightly fix the locking jackscrew of the titanium alloy connecting rod and micromotion pedicle screw. 2. The posterior thoracolumbar micro-motion fixation system according to claim 1, wherein the micro-motion pedicle screw is composed of a ball-head screw and a screw seat, the ball-head screw and the nail seat are riveted, and the ball-head screw It is fixed by the nail seat, and the nail seat and the ball stud form a rotation width, so that the ball stud rotates slightly in a limited direction in the nail seat, and the front end of the nail seat catches the ball head front of the ball stud. 3. The posterior thoracolumbar micro-motion fixation system according to claim 2, characterized in that the rotation range of the ball screw is controlled at -15 to 15 degrees. 4. The posterior thoracolumbar micro-motion fixation system according to claim 2, characterized in that the ball-head nail is ground into a pair of parallel planes in the riveting direction with the nail seat, so that the ball-head nail and the nail seat are firmly riveted. 5. The posterior thoracolumbar micro-motion fixation system according to claim 2, characterized in that there is a U-shaped groove at the rear of the screw seat, and the micro-motion pedicle screw is fixedly connected with the titanium alloy connecting rod through the U-shaped groove, The micromotion pedicle screw and the titanium alloy connecting rod are in cylindrical contact. 6. The posterior thoracolumbar micro-movement fixation system according to claim 2, characterized in that, the rear part of the nail seat is provided with an internal thread part, and the internal thread part is installed with a locking screw, and the titanium alloy connection is fixed by the locking screw. Great. 7. The posterior thoracolumbar micro-movement fixation system according to claim 2, characterized in that the front end of the nail seat has two slopes in the direction of the micro-movement of the ball screw. 8. The posterior thoracolumbar micro-motion fixation system according to claim 2, characterized in that the ball head screw and the nail seat are an assembly, and the two cannot be disassembled. 9. The posterior thoracolumbar micro-motion fixation system according to claim 1, characterized in that Ti-6Al-4V micro-motion pedicle screws, Ti-6Al-4V titanium alloy connecting rods and Ti-6Al-4V Tighten the top screw.