CN106551721A - Laterally displaced screw tail, laterally adjustable spinal screw and implantation method - Google Patents

Abstract

The invention provides a transverse displacement nail tail, a transverse adjustable spinal screw and an implantation method, wherein the screw comprises a nail tail and a nail seat arranged on an installation head of the nail tail, the top of the nail seat is provided with a bar groove for placing a connecting rod, the bar groove is sunken downwards from the top of the nail seat and penetrates through the nail seat along the radial direction, the bottom of the bar groove is a curved surface matched with the peripheral surface of the connecting rod, and the side surface of the bar groove is provided with a locking thread matched with a locking bolt; the nail tail comprises a fixing column capable of being screwed into the vertebral body and a platform located at the end part of the fixing column, an installing head used for being connected with the nail seat is arranged on the platform, and an eccentric distance is reserved between the center of the installing head and the axis of the fixing column. According to the transversely-displaced nail tail, the transversely-adjustable spinal screw and the implantation method, the nail seats are connected into a line by designing a brand-new screw, so that the installation process of the connecting rod is reliable and effective, the improper distortion of the spinal column cannot be caused, the difficulty of the operation of a doctor is reduced, and the operation effect is improved.

Description

Laterally displaced screw tail, laterally adjustable spinal screw and implantation method

technical field

The invention relates to a lateral displacement nail tail.

The invention also relates to a laterally adjustable spinal screw and an implantation method.

Background technique

The application of spinal internal fixation technology began in the 1960s and was used to surgically treat a variety of spinal diseases, such as spinal deformities, juvenile scoliosis, spinal fractures, and spinal degenerative diseases. The technique of spinal internal fixation can be briefly described as the following steps: first, select the spinal segment to be fixed, and implant anchoring devices (such as hooks or screws, etc.); then, lock the connecting device (such as a fixed rigid plate or a fixed rod) to each hook or screw, thereby restricting the relative movement inside the spinal segment and making it a stable body; finally, in this segment Bone graft materials (such as autologous bone or bone substitute materials) are placed between the vertebral bodies in the spine, and the spinal segments are expected to gradually fuse into one body within a period of time after surgery to ensure long-term stability.

Each single vertebra can be divided into front and rear. The front is the abdominal part, and the rear is the back part. The bone tissue connecting the front and the rear is called the pedicle. All the screws that enter the bone from the rear and are implanted into the vertebral body through the pedicle are collectively called pedicle screws, and the tail of the screw is usually left with a rod groove to lock the connecting rod.

The pedicle screw is currently the most commonly used anchoring device in spinal internal fixation systems. It consists of a screw tail (the threaded part implanted inside the bone) and a nail seat (the rest stays outside the bone). Generally speaking, pedicle screws are divided into fixed-angle screws (as shown in Figure 1, the screw tail and screw seat are integrated) and variable-angle screws (as shown in Figure 2, the screw tail and screw seat have a certain degree of movement. Adjustment angle) two kinds.

In a spinal fixation operation, multiple screws are usually used, and the screws are respectively implanted in each vertebral body to be fixed, and then the connecting rod is loaded into each screw groove for locking to finally achieve the purpose of fixing the spine. The implantation of screws is mainly based on the anatomical features of the target vertebral body and the limitation of the surgical space. Therefore, the position and direction of each screw entering the bone may be very different even between two adjacent vertebral bodies. The disadvantage of fixed-angle screws is that they cannot Adjusting the angle of the spine on the lateral plane, locking the connecting rod will cause excessive flexion and extension of the intervertebral body during the fixation stage, and the use of adjustable angle screws can largely avoid such problems. However, on the anterior plane of the spine, the screws implanted in different vertebral bodies may form a left-right misalignment, which will cause great difficulties in the insertion of the connecting rod, especially when multiple screws are used. Often doctors have to make certain compromises, such as aligning the screws as much as possible, making it difficult to ensure that each screw is placed in an ideal state, or bending the connecting rod to fit each screw seat, which makes the operation difficult Complicate and add some uncertainty or cause undue distortion of the spine.

Up to now, there is no spinal internal fixation device and method that can satisfactorily solve this problem.

Contents of the invention

In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a laterally displaced screw tail, a laterally adjustable spinal screw and an implantation method, which are used to solve the problem of multiple screws implanted in the vertebral body in the prior art. Difficult to line up questions.

To achieve the above purpose and other related purposes, the present invention provides a lateral displacement nail tail, the nail tail includes a fixed column that can be screwed into the vertebral body and a platform at the end of the fixed column, the platform is provided with a The mounting head connected with the nail seat has an eccentric distance between the center of the mounting head and the axis of the fixing column.

Preferably, the range of the eccentricity between the center of the installation head and the axis of the fixing column is 1mm˜5mm.

Preferably, the outer peripheral surface of the fixing post is provided with threads.

Preferably, the outer surface of the installation head is a spherical surface, and the top of the installation head is provided with an inwardly recessed non-circular installation adjustment hole.

In order to achieve the above purpose and other related purposes, the present invention also provides a laterally adjustable spinal screw. The screw includes the nail tail described in the above technical solution and a nail seat installed on the installation head of the nail tail. The top of the nail seat is provided with a The rod groove is used to place the connecting rod. The rod groove is recessed from the top of the nail seat and penetrates the nail seat in the radial direction. The bottom of the rod groove is a curved surface suitable for the outer peripheral surface of the connecting rod. Compatible locking threads.

Preferably, the nail seat includes a nail seat jacket and a sliding tension ring set in the nail seat jacket, the slide tension ring is set on the installation head of the nail tail, and the rod groove is located at the end of the nail seat jacket away from the slide tension ring.

Further preferably, the sliding tension ring is provided with a ball socket for placing the installation head, and the ball socket is provided with an opening facing the installation head, and the diameter of the opening is smaller than the maximum diameter of the installation head.

Further preferably, a plurality of extending grooves uniformly distributed along the circumferential direction are provided on the peripheral surface of the ball socket, and the extending grooves extend from the opening to an end corresponding to the opening.

Still further preferably, a limiting ring is provided on the inner peripheral surface of the nail holder outer shell facing the end of the nail tail, and the inner peripheral surface of the limiting ring fits with the outer peripheral surface of the opening of the ball socket.

Still further preferably, an inwardly recessed loose section is provided on the inner peripheral surface of the outer shell of the nail seat corresponding to the ball socket, and a gap is maintained between the loose section and the outer peripheral surface of the ball socket.

Further preferably, at least one limiting groove extending downward from the top is further provided on the side wall of the sliding tensioning ring, and a limiting nail corresponding to the limiting groove is provided on the nail holder outer cover.

Further preferably, the end of the sliding tensioning ring facing the rod groove is provided with an arc-shaped groove, and the inner peripheral surface of the arc-shaped groove corresponds to the bottom of the rod groove. When the sliding tensioning ring is installed in place, the inner peripheral surface of the arc-shaped groove is convex. out of the bottom of the rod slot.

In order to achieve the above purpose and other related purposes, the present invention also provides a method for implanting a laterally adjustable spinal screw into a vertebral body. The laterally adjustable spinal screw is as described in the above technical solution, and the implantation method includes the following steps:

1) Determine the entry point P of each screw on the vertebral body, and screw the nail tails of each screw into the vertebral body from the preset entry point P one by one;

2) Set the placement position of the connecting rod on the vertebral body, and mark the placement position of the connecting rod as the reference line L;

3) rotating the platform so that the center of the mounting head is as close as possible to the reference line L;

4) Install the nail seat on the installation head of each nail tail, and rotate the nail seat so that the axes of the rod grooves of all the nail seats are on the same straight line;

5) Insert the connecting rod into the rod groove to connect all the nail seats together;

6) Install locking bolts one by one on the top of each nail seat, the locking bolts extend into the rod groove, and match the locking thread in the rod groove.

As mentioned above, the laterally displaced screw tail, laterally adjustable spinal screw and implantation method of the present invention have the following beneficial effects:

The laterally shifted screw tail, laterally adjustable spinal screw and implantation method design a brand-new screw to realize the connection of the screw seat in a line, so that the installation process of the connecting rod is reliable and effective, and will not cause improper distortion of the spine, reducing the It reduces the difficulty of the doctor's operation and improves the effect of the operation.

Description of drawings

FIG. 1 is a schematic structural diagram of a fixed-angle screw in the prior art.

Fig. 2 is a schematic structural diagram of a variable-angle screw in the prior art.

Fig. 3 is a schematic diagram showing the structure of the laterally displaced nail tail of the present invention.

FIG. 4 is a front view of the laterally displaced nail tail shown in FIG. 3 .

Fig. 5 is a schematic diagram showing the structure of the laterally adjustable spinal screw of the present invention.

FIG. 6 is a schematic structural view of the screw seat of the laterally adjustable spinal screw shown in FIG. 5 .

FIG. 7 is a schematic perspective view of the nail holder shown in FIG. 6 .

FIG. 8 is a schematic structural view of the sliding tension ring of the nail seat shown in FIG. 6 .

9 to 14 are schematic diagrams showing the steps of the method for implanting the laterally adjustable spinal screw shown in FIG. 5 .

Component designation description

1 nail tail

11 Fixing post

12 platforms

13 mounting head

14 Mounting adjustment holes

2 nail holders

21 rod groove

22 Locking thread

23 nail seat jacket

24 sliding tensioning ring

25 socket

26 openings

27 Extension slot

28 limit circle

29 loose segment

210 limit slot

211 Limit nail

212 arc groove

3 connecting rods

4 locking bolts

5 nail tail special handle screwdriver

6 vertebrae

detailed description

The implementation of the present invention will be illustrated by specific specific examples below, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

See Figures 3 through 14. It should be noted that the structures, proportions, sizes, etc. shown in the drawings attached to this specification are only used to match the content disclosed in the specification, for those who are familiar with this technology to understand and read, and are not used to limit the implementation of the present invention. Limiting conditions, so there is no technical substantive meaning, any modification of structure, change of proportional relationship or adjustment of size, without affecting the effect and purpose of the present invention, should still fall within the scope of the present invention. within the scope covered by the disclosed technical content. At the same time, the directions and quantitative terms quoted in this specification, such as "up", "down", "left", "right", "middle" and "one", are only for the convenience of description, and It is not intended to limit the practicable scope of the present invention, and the change or adjustment of the relative relationship shall also be regarded as the practicable scope of the present invention without substantive changes in the technical content.

As shown in FIGS. 3 to 4 , the present invention provides a lateral displacement nail tail 1, the nail tail 1 includes a fixing column 11 that can be screwed into the vertebral body 6 and a platform 12 located at the end of the fixing column 11, The platform 12 is provided with an installation head 13 for connecting with the nail base 2 , and there is an eccentric distance between the center of the installation head 13 and the axis of the fixing column 11 .

By adopting the eccentric installation head 13, the position of the installation head 13 can be adjusted by rotating the fixed column 11, so that the center of the installation head 13 is as close as possible to the reference line L (i.e. the placement position of the connecting rod 3), so that it can be installed on The nail bases 2 on the installation head 13 are located on a straight line as much as possible, so that all the nail bases 2 can be connected by a connecting rod 3, and the spinal screws are located at the most ideal position on the spine, which will not cause improper distortion of the spine.

The range of the eccentric distance D between the center of the mounting head 13 and the axis of the fixed column 11 is preferably 1 mm to 5 mm, and the range of the eccentric distance D basically satisfies that the nail tail 1 is within the range of 1/4 of the rotation, that is, the The installation head 13 is as close as possible to the requirements of the reference line L.

In order to facilitate the fixing of the nail tail 1 and the vertebral body 6, the outer peripheral surface of the fixing column 11 is provided with threads.

The outer surface of the installation head 13 is preferably a spherical surface, and the top of the installation head 13 is provided with an inwardly recessed non-circular installation adjustment hole 14 . The cross-section of the installation adjustment hole 14 is preferably hexagonal, so that a hexagonal screwdriver can be inserted into the installation adjustment hole 14, and the position of the installation head 13 can be adjusted using the hexagonal screwdriver.

As shown in Figures 5 to 8, the present invention provides a laterally adjustable spinal screw, comprising the above-mentioned nail tail 1 and a nail seat 2 installed on the installation head 13 of the nail tail 1, and the top of the nail seat 2 is provided There is a rod groove 21 for placing the connecting rod 3, the rod groove 21 is recessed downward from the top of the nail seat 2 and penetrates the nail seat 2 radially, the bottom of the rod groove 21 is a curved surface adapted to the outer peripheral surface of the connecting rod 3, the rod The side of the groove 21 is provided with a locking thread 22 matched with the locking bolt 4 .

Because the nail base 2 has a certain lateral displacement relative to the fixed column 11 of the nail tail 1, if the nail base 2 is installed on the nail tail 1 in advance, when the nail tail 1 rotates, the outer circle of the nail base 2 is relatively large, which is not necessary. It is convenient to operate, so the present invention proposes an assemblable nail base design. After the nail tail 1 is fixed on the vertebral body 6, the nail base 2 is installed on the nail tail 1. The nail seat 2 that is installed on the installation head 13 can be rotated on the installation head 13, makes the axis of the bar groove 21 of a plurality of nail seats 2 be in line, makes connecting rod 3 can be placed in the bar groove 21, a plurality of bar grooves 21 together. In order to fix the connecting rod 3, a locking bolt 4 is also installed from the top of the rod groove 21, and the locking bolt 4 is matched with the locking thread 22 on the side of the rod groove 21.

A specific structure of the nail seat 2 is as follows: the nail seat 2 includes a nail seat outer cover 23 and a sliding tension ring 24 enclosed in the nail seat outer cover 23, the sliding tension ring 24 is set on the installation head 13 of the nail tail 1, and the rod The groove 21 is located at the end of the nail holder outer shell 23 away from the sliding tensioning ring 24 .

The sliding tension ring 24 is provided with a ball socket 25 for placing the mounting head 13 , and the ball socket 25 is provided with an opening 26 facing the mounting head 13 , and the diameter of the opening 26 is smaller than the maximum diameter of the mounting head 13 . The installation head 13 can rotate at multiple angles in the ball socket 25, so that the nail seat 2 can be adjusted at multiple angles.

The peripheral surface of the ball socket 25 is provided with a plurality of extending grooves 27 uniformly distributed along the circumferential direction, and the extending grooves 27 extend from the opening 26 to an end corresponding to the opening 26 . The shape of the ball socket 25 provided with the extension groove 27 is like a petal. When the installation head 13 is put into the ball socket 25 from the opening 26, the setting of the extension groove 27 can make the ball socket 25 have certain elasticity and can be slightly The external expansion ensures the smooth installation of the installation head 13; and when the connecting rod 3 is installed in the rod groove 21, the connecting rod 3 will exert a certain pressure on the sliding tension ring 24, and the setting of the extension groove 27 can make the ball socket 25 With a certain degree of elasticity, the length of the sliding tension ring 24 along the axial direction can be changed in time to adapt to the installation of the connecting rod 3 .

In order to ensure that the sliding tension ring 24 will not slip off from the nail seat outer cover 23, the inner peripheral surface of the nail seat outer cover 23 facing the end of the nail tail 1 is provided with a limit ring 28, and the inner peripheral surface of the limit ring 28 is in contact with the ball socket 25. The outer peripheral surface of the opening 26 fits.

The portion of the inner peripheral surface of the nail seat cover 23 corresponding to the ball socket 25 is provided with an inwardly recessed loose section 29 , and a gap is maintained between the loose section 29 and the outer peripheral surface of the ball socket 25 to provide a space for the ball socket 25 to deform.

The side wall of the sliding tension ring 24 is further provided with at least one limiting groove 210 extending downward from the top, and the nail seat outer cover 23 is provided with a limiting nail 211 corresponding to the limiting groove 210 . When the sliding tension ring 24 is inserted into the nail holder outer cover 23 to a predetermined position, the limiting nail 211 is stuck in the bottom of the limiting groove 210, and the relative position of the sliding tension ring 24 and the nail holder outer cover 23 is locked.

One end of the sliding tensioning ring 24 facing the rod groove 21 is provided with an arc groove 212, and the inner peripheral surface of the arc groove 212 corresponds to the bottom of the rod groove 21. When the sliding tensioning ring 24 is installed in place, the inner surface of the arc groove 212 The peripheral surface protrudes from the bottom of the rod groove 21 . After connecting rod 3 is installed in rod groove 21, load onto locking bolt 4 from the top of rod groove 21, because the inner peripheral surface of arc-shaped groove 212 protrudes from the bottom of rod groove 21, connecting rod 3 will meet arc-shaped groove. 212 exerts a certain pressure to make the sliding tension ring 24 move downwards. At this time, the ball socket 25 deforms and locks the installation head 13, so that the overall structure of the laterally adjustable spinal screw is more stable.

The method for implanting the above-mentioned transversely adjustable spinal screw into the vertebral body comprises the following steps:

1) Determine the nail entry point P of each screw on the vertebral body 6, and screw the nail tails 1 of each screw into the vertebral body 6 from the preset nail entry point P one by one by using a screwdriver 5 dedicated to the nail tail;

2) Set the placement position of the connecting rod 3 on the vertebral body 6, and mark the placement position of the connecting rod 3 as the reference line L;

3) Use a hexagonal screwdriver to insert into the installation adjustment hole 14, and rotate the platform 12 so that the center of the installation head 13 is as close as possible to the reference line L;

4) Place the installation head 13 of each nail base 1 in the ball socket 25 of the nail base 2, connect the nail tail 1 with the nail base 2, and rotate the nail base 2 so that the axes of the rod grooves 21 of all nail bases 2 are at the on the same straight line;

5) insert the connecting rod 3 into the rod groove 21, so that all the nail seats 2 are connected as one;

6) Install the locking bolts 4 one by one on the top of each nail seat 2, the locking bolts 4 extend into the rod groove 21, and cooperate with the locking thread 22 in the rod groove 21, at this time, the connecting rod 3 will meet the arc shape The groove 212 exerts a certain pressure, so that the sliding tension ring 24 moves downward, and the ball socket 25 is deformed to lock the installation head 13 .

To sum up, the laterally shifted nail tail, laterally adjustable spinal screw and implantation method of the present invention, by designing a brand-new screw, realizes that the screw seat is connected in a line, so that the installation process of the connecting rod is reliable and effective, and will not cause spinal cord damage. Improper twisting reduces the difficulty of the doctor's operation and improves the effect of the operation. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial application value.

The above-mentioned embodiments only illustrate the principles and effects of the present invention, but are not intended to limit the present invention. Anyone skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical ideas disclosed in the present invention should still be covered by the claims of the present invention.

Claims (13)

1. A laterally displaced nail tail (1), characterized in that: the nail tail (1) comprises a fixing column (11) that can be screwed into the vertebral body (6) and a fixing column (11) located at the fixing column (11). ), the platform (12) at the end of the platform (12) is provided with a mounting head (13) for connecting with the nail seat (2), and the center of the mounting head (13) is connected to the fixing column (11 ) has an eccentricity between the axes. 2. The lateral displacement nail tail (1) according to claim 1, characterized in that: the range of eccentricity between the center of the installation head (13) and the axis of the fixing column (11) is 1mm ~5mm. 3. The lateral displacement nail tail (1) according to claim 1, characterized in that: the outer peripheral surface of the fixing column (11) is provided with threads. 4. The lateral displacement nail tail (1) according to claim 1, characterized in that: the outer surface of the installation head (13) is a spherical surface, and the top of the installation head (13) is provided with an inward depression non-circular mounting adjustment holes (14). 5. A laterally adjustable spinal screw, characterized in that: the screw comprises the nail tail (1) according to any one of claims 1 to 4 and the screw tail (1) installed on the installation head (13) of the nail tail (1) A nail seat (2), the top of the nail seat (2) is provided with a rod groove (21) for placing the connecting rod (3), and the rod groove (21) is downward from the top of the nail seat (2) Concave and run through the nail seat (2) in the radial direction, the bottom of the rod groove (21) is a curved surface adapted to the outer peripheral surface of the connecting rod (3), and the side of the rod groove (21) is provided with Locking thread (22) cooperating with locking bolt (4). 6. The laterally adjustable spinal screw according to claim 5, characterized in that: the nail seat (2) comprises a nail seat outer cover (23) and a sliding tension ring set in the nail seat outer cover (23) (24), the sliding tension ring (24) is sleeved on the installation head (13) of the nail tail (1), and the rod groove (21) is located at the nail seat outer cover (23) away from the sliding One end of tightening ring (24). 7. The laterally adjustable spinal screw according to claim 6, characterized in that: the sliding tension ring (24) is provided with a ball socket (25) for placing the installation head (13), and the ball socket ( 25) An opening (26) is provided facing the mounting head (13), the diameter of said opening (26) being smaller than the maximum diameter of said mounting head (13). 8. The laterally adjustable spinal screw according to claim 7, characterized in that: the peripheral surface of the ball socket (25) is provided with a plurality of extending grooves (27) uniformly distributed along the circumferential direction, and the extending grooves (27) extends from the opening (26) to an end corresponding to the opening (26). 9. The laterally adjustable spinal screw according to claim 7, characterized in that: the inner peripheral surface of the nail seat outer cover (23) facing the end of the nail tail (1) is provided with a limiting ring (28), the limiting ring (28) is The inner peripheral surface of the position ring (28) matches the outer peripheral surface of the opening (26) of the ball socket (25). 10. The laterally adjustable spinal screw according to claim 7, characterized in that: the part of the inner peripheral surface of the nail base outer cover (23) corresponding to the ball socket (25) is provided with an inwardly concave loose section (29), maintaining a gap between the loose section (29) and the outer peripheral surface of the ball socket (25). 11. The laterally adjustable spinal screw according to claim 6, characterized in that: the side wall of the sliding tensioning ring (24) is further provided with at least one limiting groove (210) extending downward from the top, A limiting nail (211) corresponding to the limiting groove (210) is provided on the nail seat outer cover (23). 12. The laterally adjustable spinal screw according to claim 6, characterized in that: the end of the sliding tensioning ring (24) facing the rod groove (21) is provided with an arc-shaped groove (212), and the arc-shaped groove (212) is The inner peripheral surface of the arc-shaped groove (212) corresponds to the bottom of the rod groove (21). When the sliding tension ring (24) is installed in place, the inner peripheral surface of the arc-shaped groove (212) protrudes from the The bottom of the rod groove (21). 13. A method for implanting a laterally adjustable spinal screw into a vertebral body, said laterally adjustable spinal screw as described in any one of claims 5 to 12, characterized in that said implantation method comprises the following steps: 1) Determine the entry point P of each screw on the vertebral body (6), and screw the nail tail (1) of each screw into the vertebral body (6) from the preset entry point P one by one. )Inside; 2) setting the placement position of the connecting rod (3) on the vertebral body (6), marking the placement position of the connecting rod (3) as a reference line L; 3) rotating the platform (12) so that the center of the installation head (13) is as close as possible to the reference line L; 4) install the nail seat (2) on the installation head (13) of each nail tail (1), and rotate the nail seat (2) so that the axes of the rod grooves (21) of all nail seats (2) lie on the same straight line; 5) Insert the connecting rod (3) into the rod groove (21), so that all the nail seats (2) are connected as one; 6) Install locking bolts (4) one by one on the top of each nail seat (2), and the locking bolts (4) extend into the rod groove (21), and lock the locking bolts (4) in the rod groove (21) Thread (22) matches.