Minimally invasive pedicle screw rod in-vitro auxiliary lifting reduction system

Abstract

The utility model discloses a minimally invasive pedicle screw rod in-vitro auxiliary lifting and resetting system, which comprises two in-vitro extension rods, two in-vitro lifting and resetting rods, two in-vitro lifting and resetting rods, a lifting and resetting rod and a lifting and resetting rod, and is characterized in that the two in-vitro extension rods are respectively matched with pedicle screws which are embedded into a slipped adjacent vertebral body; the front end of the in-vitro extension rod and the head of the minimally invasive pedicle screw are fixedly installed in a matched mode, and the rear end of the in-vitro extension rod is provided with a nut in a threaded fit mode. The connecting rod is perpendicular to the in-vitro extension rod, and adjusting holes matched with the in-vitro extension rod to achieve angle adjustment of the pedicle screw are formed in the positions, corresponding to the in-vitro extension rod, of the connecting rod; the nut is matched with the connecting rod, so that the in-vitro extension rod moves along the axial direction of the in-vitro extension rod, and the lifting reset of the slipped vertebral body is further realized. According to the vertebral body lifting and resetting device, lifting and resetting of the vertebral body and fixing of a screw-rod system can be achieved, the problems that in the prior art, the direction of screws swings and the distance between the screws is reduced during lifting and resetting are solved, and the operation effect is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of medical devices, in particular to an in vitro auxiliary lifting and resetting system for minimally invasive pedicle screws and rods. Background Art

[0002] The development of spinal pedicle screw fixation technology is an important milestone in the history of spinal surgery and has strongly promoted the development of spinal surgery. In 1949, Michele first described the anatomical morphology of the pedicle and entered the vertebral body through the pedicle from the posterior approach to obtain a biopsy specimen. In 1959, Boucher1 first applied the pedicle fixation technique to fix the screw through the inferior articular process through the articular process joint into the pedicle. In 1962, Harrington first used the Harrington rod for the correction of scoliosis. The system consists of a lamina hook and a stainless steel internal fixation rod connected to it, which effectively treats scoliosis and pioneered the use of implants to correct spinal deformity and fix fusion. In 1982, Luque proposed the spinal fixation technique of the sublamina segment wire and Luque rod. In 1983, Denis proposed the "three-column theory", which divides the spine into "anterior, middle and posterior columns", and the pedicle is a channel that penetrates and connects the three columns. The "middle column" plays a key role in the stability of the spine. In 1986, Roy-Camille pioneered the method of inserting pedicle screws and introduced the transpedicular spinal instrument fixation system, which was widely used in clinical practice.

[0003] The pedicle is the strongest structure of the spine and can withstand lateral bending stress, rotational stress, and extension and flexion stress. Pedicle screw fixation provides good biomechanical stability and can achieve axial (compression or distraction), torsion, and sagittal correction. Pedicle screws can firmly fix the spine, thereby improving the fusion rate. Goel et al. confirmed through a cadaver model that instrument fixation of the pedicle system can reduce 70% of spinal extension and flexion activities and 65% of lateral flexion and axial movement; Kotani et al. confirmed through a study of a living sheep model that the pedicle fixation system can evenly distribute the load of the anterior and middle columns of the spine. Because pedicle screw fixation fixes the pedicle and vertebral body at the same time, it provides three-column stability, so it can apply greater correction force and stability to the spine. The application of thoracolumbar internal fixation in China originated in the 1980s. It was first used in patients with thoracolumbar fractures. Later, it was gradually promoted and widely used in patients with thoracolumbar degeneration, deformity, tumors, etc.

[0004] With the development of minimally invasive spinal technology, minimally invasive treatment of lumbar spondylolisthesis has also been developed, and the open reduction screw system has also developed into a percutaneous screw rod system, which is widely used in minimally invasive spinal fusion. The existing minimally invasive treatment reduction technology for lumbar spondylolisthesis mainly uses the lifting and reduction of the percutaneous screw rod system. Through the height difference of the screw and the height difference of the vertebral body after the slippage, after being fixed by the tail end screw rod, the head end nut pressurizes the connecting rod to lift the screw on the slipped vertebral body, thereby driving the reduction of the slipped vertebral body. However, the system is percutaneous, so the direction of the screw cannot be fixed. Therefore, the swing of the screw direction is not easy to control. During the reduction, the universal screw will tilt, the lifting effect will be weakened, and the distance between the two pedicle screws will be reduced when the nut is locked. Summary of the invention

[0005] Purpose of the invention: In view of the above-mentioned deficiencies, the utility model provides an extracorporeal assisted lifting and reduction system for a minimally invasive pedicle screw rod, which adds an extracorporeal control device to the existing minimally invasive pedicle screws to solve the problem of directional swing of the minimally invasive pedicle screws and the problem of reduced spacing between the minimally invasive pedicle screws during lifting and reduction in the prior art.

[0006] Technical solution: The present invention provides a minimally invasive pedicle screw rod in vitro auxiliary lifting and reduction system, comprising:

[0007] There are two in vitro extension rods, which are respectively installed with the pedicle screws inserted into the adjacent vertebral body with slippage; the front end of the in vitro extension rod is fixedly installed with the head of the pedicle screw, and the rear end is provided with a nut through threaded cooperation;

[0008] A connecting rod is arranged perpendicular to the external extension rod, and adjustment holes are respectively provided on the connecting rod at positions corresponding to the external extension rod for cooperating with the external extension rod to adjust the angle of the pedicle screw;

[0009] The nut cooperates with the connecting rod to realize the axial movement of the external extension rod, thereby realizing the lifting and resetting of the slipped vertebral body.

[0010] Specifically, a rear end of the in vitro extension rod is provided with a rear threaded section, and the rear threaded section is provided with two opposite matching surfaces corresponding to the adjustment hole.

[0011] More specifically, the mating surface is a plane or a curved surface, and the adjustment hole is arranged corresponding to the mating position thereof.

[0012] More specifically, one of the two extracorporeal extension rods is designed as a through-hole structure, on which the nut is arranged at a position above the connecting rod, and a locking piece is passed through the hollow structure, and the locking piece cooperates with a screw block provided in the head of the pedicle screw placed in the slipped vertebra, so as to lock the connecting rod passed through the head of the pedicle screw thereon after the slipped vertebra is lifted and reduced.

[0013] Furthermore, the locking member is designed in a T-shaped structure.

[0014] Furthermore, nuts are provided at positions above and below the connecting rod on the other external extension rod.

[0015] Specifically, the nut is designed as an external hexagonal nut.

[0016] Beneficial effects: Through the designed external extension rod, connecting rod and locking member, the present invention can increase controllability outside the body to achieve the lifting and reduction of the vertebral body and the fixation of the screw-rod system, improve the reduction effect, solve the problems of the direction swing of the screw and the reduction of the screw spacing during lifting and reduction in the prior art, and improve the surgical effect. Description of the Drawings

[0017] In order to more clearly illustrate the technical solutions in one or more embodiments or the prior art of this specification, the following will briefly introduce the drawings required to be used in the description of one or more embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in this specification. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0018] Figure 1 It is a rendering of the overall structure of the present utility model;

[0019] Figure 2 It is a structural line drawing of another angle of the present utility model;

[0020] Figure 3 It is a line example drawing of the locking member of the present utility model.

[0021] Among them, 10 is a pedicle screw, 20 is an external extension rod, 30 is a connecting rod, and 40 is a locking member;

[0022] 11 is a screw body, 12 is a screw head, and 13 is a screw block; 21 is a front threaded section, 22 is a rear threaded section, 23 is a mating surface, 24 is a fixing nut, 25 is an adjusting nut; 31 is an adjusting hole. Detailed Embodiments

[0023] To make the objectives, features, and advantages of the present utility model more obvious and understandable, the following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, rather than all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present utility model.

[0024] The minimally invasive pedicle screw-rod external auxiliary lifting and reduction system of the present utility model is as shown in Figure 1 , 2 and includes pedicle screws 10, an external extension rod 20, a connecting rod 30 and a locking member 40.

[0025] In the present utility model, there are two pedicle screws 10, which are respectively used for being inserted into adjacent slipped vertebrae, and include a screw body 11 with external threads at its front end and a screw head 12 with internal threads at its rear end. Among them, the screw head 12 is designed as a "U"-shaped structure for passing through and connecting a connecting rod for at least two pedicle screws 10; a screw block 13 is further provided in the screw head 12, and the screw block 13 is provided with external threads corresponding to and cooperating with the internal threads of the screw head 12, so as to tighten and fix the connecting rod when the connecting rod passes through the screw head 12.

[0026] The external extension rod 20 is fixedly installed in cooperation with the screw head 12 of the pedicle screw 10. Specifically, the front end of the external extension rod 20 is provided with a front thread section 21 that cooperates with the internal threads of the screw head 12 of the pedicle screw 10, and the external extension rod 20 is installed in the screw head 12 of the pedicle screw 10 through thread cooperation; the rear end of the external extension rod 20 is provided with a rear thread section 22, and two opposite mating surfaces 23 are provided on the rear thread section 22. Specifically, a piece can be cut off along the axial direction on two opposite sides of the rear thread section 22 of the external extension rod 20 to form two opposite mating surfaces 23, and the mating surface 23 can be a plane or a curved surface.

[0027] The connecting rod 30 is arranged perpendicular to the external extension rod 20, and through adjusting holes 31 are respectively opened at positions corresponding to the two external extension rods 20 on the connecting rod 30. The external extension rods 20 pass through the adjusting holes 31, and the adjusting holes 31 extend along the length direction of the connecting rod 30, so that the external extension rods 20 can move along the length direction of the connecting rod 30 in the adjusting holes 31.

[0028] In the present utility model, the mating surfaces 23 provided on the rear thread section 22 of the external extension rod 20 cooperate with the adjusting holes 31; if the mating surface 23 is a curved surface, the adjusting holes 31 are also set as corresponding curved surfaces at the positions where they cooperate.

[0029] Further, among the two external extension rods 20, one of them is designed as a through hollow structure, which can be defined as a hollow extension rod, and it passes through the screw head 12 corresponding to the pedicle screw 10 installed on the slipped vertebra; the other can be defined as a solid extension rod, and it passes through the screw head 12 corresponding to the pedicle screw 10 installed on the other vertebra.

[0030] In the present utility model, after the solid extension rod is passed through the adjustment hole 31 of the connecting rod 30, fixing nuts 24 can be arranged at positions above and below the connecting rod 30 respectively, which are used to lock and fix after adjusting the direction of the corresponding pedicle screw 10 through the solid extension rod, so as to avoid the problem of the direction swing of the corresponding pedicle screw 10 during the lifting process. The hollow extension rod is passed through another adjustment hole 31 on the connecting rod 30, and an adjustment nut 25 is arranged at a position above the connecting rod 30, which is used to make the hollow extension rod move axially in the adjustment hole 31 of the connecting rod 30 by rotating the adjustment nut 25, so as to perform lifting and reduction on the corresponding vertebral body.

[0031] In the present utility model, the fixing nut and / or the adjustment nut can be designed as an external hexagon nut.

[0032] In the present utility model, a locking member 40 is arranged inside the hollow extension rod, and the front end thereof is matched with a screw block 13 inside the screw head 12 of the pedicle screw 10 corresponding to the hollow extension rod, so as to control the screw block 13 to lock the connecting rod after the lifting and reduction of the vertebral body are completed.

[0033] In the embodiment of the present utility model, with reference to Figure 3 , the locking member 40 can be designed as a T-shaped structure to facilitate the operation of the locking member 40.

[0034] The working principle of the present utility model is as follows:

[0035] The pedicle screws 10 are respectively inserted into adjacent slipped vertebral bodies through the skin. The connecting rod is passed through the screw heads 12 of the two pedicle screws 10. The screw block 13 in the screw head 12 of the pedicle screw 10 corresponding to the slipped vertebral body does not lock the connecting rod temporarily, and the screw block 13 in the screw head 12 of the pedicle screw 10 corresponding to the other vertebral body locks the connecting rod. An external extension rod 20 is passed through the screw heads 12 of the two pedicle screws 10, and a connecting rod 30 is installed between the two external extension rods 20. The external extension rod 20 corresponding to the slipped vertebral body is located above the connecting rod 30 and an adjustment nut 25 is installed; the external extension rods 20 corresponding to the other vertebral body are respectively installed with fixing nuts 24 above and below the connecting rod 30, and after the external extension rod 20 is adjusted in place, it is locked and fixed to avoid the problem of the direction swing of the corresponding pedicle screw 10 during the lifting process.

[0036] By screwing in the adjusting nut 25, the corresponding external extension rod 20 moves axially towards its rear end (i.e., away from the vertebral segment), thereby driving the corresponding pedicle screw 10 to move correspondingly, and further realizing the lifting of the slipped vertebral body. After the slipped vertebral body is lifted and reduced, the locking member 40 is inserted into the corresponding external extension rod 20, and cooperates with the screw block 13 in the screw head 12 of the corresponding pedicle screw 10 to lock the connecting rod, and finally complete the fixation of the nail-rod system of the present utility model.

[0037] Through the designed external extension rod, connecting rod and locking member, the present invention can increase the controllability outside the body to realize the lifting and reduction of the vertebral body and the fixation of the nail-rod system, improve the reduction effect, and solve the problems of the direction swing of the screw and the reduction of the screw spacing during the lifting and reduction in the prior art, and improve the surgical effect.

[0038] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0039] In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, "a plurality" means two or more, unless otherwise specifically defined.

[0040] The above is only the specific implementation manner of the present utility model, but the protection scope of the present utility model is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present utility model, and all should be covered by the protection scope of the present utility model. Therefore, the protection scope of the present utility model should be subject to the protection scope of the claims.

Claims

1. A minimally invasive pedicle screw-rod external auxiliary lifting and reduction system, characterized in that, Comprising: Two external extension rods, which are respectively installed in cooperation with the pedicle screws inserted into the adjacent vertebrae with slippage; The front end of the external extension rod is fixedly installed in cooperation with the head of the pedicle screw, and the nut is provided at the rear end through thread fit; A connecting rod, which is arranged perpendicular to the external extension rod, and adjusting holes for realizing the angle adjustment of the pedicle screw in cooperation with the external extension rod are respectively formed at positions corresponding to the external extension rod thereon; The nut cooperates with the connecting rod to realize the axial movement of the external extension rod, thereby realizing the lifting and reduction of the slipped vertebra; Among the two external extension rods, one of them is designed as a through hollow structure, and the nut is arranged at a position above the connecting rod. A locking member is inserted into the hollow structure, and the locking member cooperates with a screw block arranged in the head of the pedicle screw placed in the slipped vertebra to lock the connecting rod in the head of the pedicle screw inserted through it after the slipped vertebra is lifted and reduced.

2. The minimally invasive pedicle screw-rod external assisted lifting and reduction system according to claim 1, wherein The rear end of the external extension rod is provided with a rear threaded section, and two opposite mating surfaces corresponding to the adjusting holes are arranged on the rear threaded section.

3. The minimally invasive pedicle screw-rod external assisted lifting and reduction system according to claim 2, wherein The mating surface is a plane or a curved surface, and the adjusting hole is correspondingly arranged at the mating position therewith.

4. The minimally invasive pedicle screw-rod external assisted lifting and reduction system according to claim 1, wherein The locking member is designed as a T-shaped structure.

5. The minimally invasive pedicle screw-rod external auxiliary lifting and reduction system according to claim 1, wherein Nuts are arranged at positions above and below the connecting rod on the other external extension rod.

6. The minimally invasive pedicle screw-rod external auxiliary lifting and reduction system according to any one of claims 1 or 5, characterized in that, The nut is designed as an external hexagonal nut.

Images