CN204814138U - Chest lumbar vertebrae way of escape flexible fixation system - Google Patents

Abstract

The utility model belongs to the technical field of orthopedic medical devices and specifically relates to when chest lumbar vertebrae pathological change or damage for the chest lumbar vertebrae way of escape flexible fixation system that fix is carried out the chest lumbar vertebrae. This system includes two pedicle of vertebral arch screws, a jackscrew that plays the ni -Ti spring stick of two pedicle of vertebral arch screw effects of flexonics and be used for fixed ni -Ti spring stick of locking and pedicle of vertebral arch screw. Ni -Ti spring bar gauge check do: 2.24-2.99mm in the silk footpath, pitch diameter 5mm. The utility model discloses a chest lumbar vertebrae way of escape flexible fixation system combines human biomechanics correlation theory to the postoperative complication problem of the strong fixing system existence of present mainstream, is the stable solution of the human lumbar vertebrae of reconstruction from the proposition of mechanics angle. All design parameters of this system directly come from compatriots' anatomy of spine data, can satisfy chest lumbar vertebrae internal fixation operation demand, and fixed reaching recovers respond well.

Description

Thoracolumbar Posterior Flexible Fixation System

technical field

The utility model relates to the field of orthopedic medical devices, in particular to a thoracolumbar posterior flexible 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 a flexible internal fixation system arises at the historic moment. In the last 30 years, scholars from all over the world have been continuously researching flexible internal fixation systems, but so far, there are not many flexible internal fixation systems that are more mature and applied to the market. There are two main representatives, namely 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 flexible fixation system for the posterior thoracolumbar spine with a simple and reliable structure.

Utility model content

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

The technical scheme of the utility model is:

A thoracolumbar posterior flexible fixation system, the system includes two pedicle screws, a Ni-Ti spring rod that flexibly connects the two pedicle screws, and a Ni-Ti spring rod and vertebral rod for locking and fixing. The top wire of the pedicle screw.

In the thoracolumbar posterior flexible fixation system, the middle part of the structure of the Ni-Ti spring rod is two coils of springs, the two ends of the structure of the Ni-Ti spring rod are straight rods, and the Ni-Ti spring rod passes through the straight rod and the vertebral arch. Root screw fixed connection.

In the thoracolumbar posterior flexible fixation system, the external thread part of the pedicle screw has a conical structure, and the tail of the pedicle screw has a U-shaped groove, and the pedicle screw is fixed with the Ni-Ti spring rod through the U-shaped groove Connection, the pedicle screw is in cylindrical contact with the Ni-Ti spring rod.

The flexible fixation system for the posterior thoracolumbar spine has a taper range of 1 to 3 degrees.

In the thoracolumbar posterior flexible fixation system, the tail of the pedicle screw is provided with an internal thread part, and the internal thread part is equipped with a top wire, and the Ni-Ti spring rod is fixed by the top wire.

The specifications of the Ni-Ti spring rods in the posterior thoracolumbar flexible fixation system are: wire diameter 2.24-2.99 mm, median diameter 5 mm.

In the thoracolumbar posterior flexible fixation system, the pedicle screws are titanium alloy pedicle screws, and the top wires are titanium alloy top wires.

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

1. The posterior thoracolumbar flexible fixation system provided by the utility model is composed of pedicle screws, Ni-Ti spring rods connected to the pedicle screws, and locking jackscrews. The locking jackscrews are used to fix the Ni-Ti spring rods , with simple structure and high reliability;

2. The middle part of the Ni-Ti spring rod of the utility model is two coils of spring, and the two ends of the Ni-Ti spring rod are straight rods. The two coils of spring in the middle part can produce elasticity under the stress of physiological movements such as bending of the spine. Deformation, maintain the normal activities of the spine. The pedicle screw adopts tapered screw, which can effectively improve the strength of the weak part of the screw root;

3. The metal flexible system of the utility model has superior mechanical properties and good biocompatibility with human tissues;

4. 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 thoracolumbar posterior flexible fixation system according to an embodiment of the present invention;

Fig. 2 is a schematic diagram of a Ni-Ti spring rod of a flexible fixation system for the posterior thoracolumbar spine according to an embodiment of the present invention;

Fig. 3 is a schematic diagram of the pedicle screws of the thoracolumbar posterior flexible fixation system according to an embodiment of the present invention;

4( a )-( b ) are schematic diagrams of top wires of the posterior flexible fixation system for thoracolumbar spine according to an embodiment of the present invention. Wherein, Fig. 4(a) is a top view; Fig. 4(b) is a main view.

In the figure, 1, spring rod; 2, pedicle screw; 3, top wire; 4, straight rod; 5, spring; 6, U-shaped groove; 7, internal thread part; 8, external thread part.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is set forth in further detail.

Referring to Fig. 1, Fig. 2, Fig. 3, and Fig. 4(a)-(b), the utility model of the thoracolumbar posterior flexible fixation system includes two pedicle screws 2, one for flexible connection of two pedicle screws 2 Ni-Ti spring rods 1 and jackscrews 3 for locking and fixing the Ni-Ti spring rods 1 and pedicle screws 2.

As shown in Figure 2, the middle part of the structure of the Ni-Ti spring rod 1 is two coils of spring 5, and the spring 5 makes the Ni-Ti spring rod 1 have certain flexibility, which can meet the normal physiological activity requirements of the thoracolumbar spine. The two ends of the structure of 1 are straight rods 4, and the straight rods 4 can be conveniently fixedly connected with the pedicle screws 2.

As shown in Figure 3 and Figure 4(a)-(b), the external thread portion 8 of the pedicle screw 2 is designed to be tapered (the taper range is 1 to 3 degrees), which can effectively improve the root of the pedicle screw 2. The strength of the pedicle screw 2 has always been the stress concentration point of the entire system, and this design can reduce the risk of the pedicle screw 2 breaking from the root. There is a U-shaped groove 6 at the end of the pedicle screw 2, and the pedicle screw 2 is fixedly connected with the Ni-Ti spring rod 1 through the U-shaped groove 6, and the pedicle screw 2 and the Ni-Ti spring rod 1 are in cylindrical contact Solid and reliable. The internal thread part 7 at the tail of the pedicle screw 2 is used to screw into the top wire 3, and the Ni-Ti spring rod 1 is fixed by the top wire 3.

When implanting the thoracolumbar posterior flexible fixation system, first determine the diseased segment of the patient’s spine, implant pedicle screws 2 according to requirements, and then select the appropriate size Ni-Ti spring rod 1 to place on the pedicle screws 2 In the U-shaped groove 6, screw the top screw 3 at last, and the implantation process is safe and quick.

According to a preferred embodiment of the present invention, the Ni-Ti spring rod is a key component of the NTS system, which is composed of nickel (50.8-51.8wt%) and the balance of titanium. Referring to the relevant mechanical experiment data, the specifications of the Ni-Ti spring rods are wire diameter 2.24-2.99mm and middle diameter 5mm. The stiffness of the Ni-Ti spring rod of this size matches the normal physiological load of the human body, which can avoid spinal tissue damage and damage to the fixation device. The length of the Ni-Ti spring rod and the length and diameter of the pedicle screw can be customized according to the individual differences of patients. In addition, the pedicle screw and top wire are made of titanium alloy.

The results of the examples show that the thoracolumbar posterior flexible 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 a solution to reconstruct the stability of the human lumbar spine from a mechanical point of view. plan. 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 (7)

1. A thoracolumbar posterior flexible fixation system is characterized in that the system comprises two pedicle screws, a Ni-Ti spring rod that flexibly connects the two pedicle screws and is used for locking and fixing Ni - Ti spring bar and top wire for pedicle screw. 2. The posterior flexible fixation system of thoracolumbar spine according to claim 1 is characterized in that, the middle part of the structure of the Ni-Ti spring rod is a two-ring spring, and the structure two ends of the Ni-Ti spring rod are straight rods, and the Ni-Ti spring rod is a straight rod. -Ti spring rods are fixedly connected with pedicle screws through straight rods. 3. The posterior thoracolumbar flexible fixation system according to claim 1, characterized in that the external threaded portion of the pedicle screw is a tapered structure, the tail of the pedicle screw is provided with a U-shaped groove, and the pedicle screw passes through The U-shaped groove is fixedly connected with the Ni-Ti spring rod, and the pedicle screw is in cylindrical contact with the Ni-Ti spring rod. 4. The posterior flexible fixation system for thoracolumbar spine according to claim 3, characterized in that the range of taper is 1-3 degrees. 5. The thoracolumbar posterior flexible fixation system according to claim 1 or 3, characterized in that, the tail of the pedicle screw is provided with an internal thread part, and the internal thread part is equipped with a top screw, and the Ni-Ti spring rod is fixed by the top screw . 6 . The posterior flexible fixation system for thoracolumbar spine according to claim 1 , wherein the specifications of the Ni-Ti spring rods are: the wire diameter is 2.24-2.99 mm, and the middle diameter is 5 mm. 7. The posterior flexible fixation system for thoracolumbar spine according to claim 1, wherein the pedicle screw is a pedicle screw made of titanium alloy, and the top wire is made of titanium alloy.