CN112353474A

CN112353474A - Universal pedicle screw

Info

Publication number: CN112353474A
Application number: CN202011354959.7A
Authority: CN
Inventors: 赵天明
Original assignee: Changzhou Kanghui Medical Innovation Co Ltd
Current assignee: Changzhou Kanghui Medical Innovation Co Ltd
Priority date: 2020-11-20
Filing date: 2020-11-27
Publication date: 2021-02-12
Also published as: CN213963600U

Abstract

The invention relates to a universal pedicle screw, which comprises a screw seat, a bone screw and a middle body, wherein one end of the screw seat is provided with a U-shaped groove, the other end of the screw seat is provided with a through hole, and one end of the through hole, which is far away from the U-shaped groove, is of a deflection angle structure; the bone screw comprises a nail body and a pair of C-shaped hemispherical rings, wherein the C-shaped hemispherical rings are detachably arranged at the head part of the nail body; the middle body is arranged in the screw seat; the nail body penetrates into the screw seat from the end of the through hole of the screw seat and is matched with the C-shaped hemispherical ring in the through hole. The invention has simple structure, convenient assembly, unlimited nail body diameter and large swing angle, and meets the requirement of the pedicle screw in special operation conditions.

Description

Universal pedicle screw

Technical Field

The invention belongs to the technical field of orthopedic medical instruments, and particularly relates to a universal pedicle screw.

Background

The existing pedicle screws for the posterior spinal rod internal fixation operation mainly comprise uniaxial pedicle screws and universal pedicle screws; because the universal pedicle screw operation is convenient for installing the connecting rod, the universal pedicle screw operation is most used in clinic. At present, the universal screw adopts a top-loading process, namely, the bone screw is loaded from the end of a U-shaped groove of a screw seat, the assembly mode ensures that the bone screw is not separated from the lower part of the screw seat, the strength of the screw seat is ensured, and a bottom hole penetrating through the bone screw is not too large under the screw seat, so that the diameter of the assembled bone screw is not large, the diameter is limited, and the swing angle of the bone screw is generally smaller than 25 degrees. The above characteristics lead to that the universal screw can not meet some special requirements in clinic, for example, the screw with large deflection angle and thick diameter is needed for fixing the sacroiliac joint in spinal orthopedic surgery.

Disclosure of Invention

The invention aims to provide a universal pedicle screw to solve the problem of limited diameter of a bone screw.

The universal pedicle screw is realized by the following steps:

a universal pedicle screw comprises

The screw comprises a screw seat, wherein one end of the screw seat is provided with a U-shaped groove, the other end of the screw seat is provided with a through hole, and one end of the through hole, which is far away from the U-shaped groove, is of a deflection angle structure;

a bone screw including a shank and a pair of C-shaped hemispherical rings detachably mounted on a head of the shank;

an intermediate body disposed within the screw seat;

the nail body penetrates into the screw seat from the end where the through hole of the screw seat is located and is matched with the C-shaped hemispherical ring located in the through hole.

Further, the top of the nail body is provided with an installation part, the installation part is provided with a conical step, and a conical groove matched with the conical step is formed in the inner annular surface of the C-shaped hemispherical ring.

Further, the outer diameter of the upper end of the tapered step is smaller than that of the lower end of the tapered step.

Furthermore, an annular inner groove is formed in the inner wall of the end portion, facing the U-shaped groove, of the through hole, and an inclined angle hole is formed in one end, far away from the U-shaped groove, of the through hole.

Further, the deflection angle between the axial direction of the deflection angle hole and the axial direction of the screw seat is 7-23 degrees.

Further preferably, the declination angle α is 15 °.

Furthermore, the inner diameter of the bottom of the inclined angle hole is larger than the outer diameter of the mounting part and smaller than the outer diameter of a ball head formed by the two C-shaped semispherical rings.

Furthermore, the intermediate body is of an annular structure, and a C-shaped groove is formed in the top of the intermediate body.

Furthermore, a limiting step is arranged on the outer ring surface of the top of the C-shaped hemispherical ring and matched with the bottom of the intermediate body.

Furthermore, riveting holes are formed in the outer walls of the two sides of the screw seat, and sinking grooves corresponding to the riveting holes are formed in the outer walls of the two sides of the intermediate body.

Furthermore, the inner walls of the two sides of the U-shaped groove are concave cambered surfaces, and inner threads are arranged on the inner walls of the U-shaped groove.

After the technical scheme is adopted, the invention has the beneficial effects that:

(1) the nail body and the ball head of the bone screw are designed in a split mode, the nail body can be installed from the end where the through hole of the screw seat is located, the ball head formed by the pair of C-shaped hemispherical rings is used for being locked in the screw seat, the bone screw is convenient and simple to assemble, the diameter of the nail body is not limited, and the requirements for the bone screws with different specifications can be met.

(2) Due to the fact that the declination angle structure is arranged, the swing angle of the bone screw can be increased, the swing angle towards the declination angle direction can be increased to 50 degrees, the sacroiliac joint can be well fixed, and therefore the application range of the pedicle screw is enlarged.

Drawings

The invention is further illustrated with reference to the following figures and examples.

FIG. 1 is a block diagram of a universal pedicle screw of a preferred embodiment of the invention;

FIG. 2 is an exploded view of the universal pedicle screw of the preferred embodiment of the invention;

FIG. 3 is a sagittal sectional view of a preferred embodiment universal pedicle screw of the invention;

FIG. 4 is an enlarged view of portion A of FIG. 3;

FIG. 5 is a cross-sectional view in the horizontal plane of the universal pedicle screw of the preferred embodiment of the invention;

FIG. 6 is an enlarged view of portion B of FIG. 5;

FIG. 7 is a cross-sectional view in the horizontal plane of the screw head of the universal pedicle screw of the preferred embodiment of the invention;

FIG. 8 is a block diagram of the shank of the universal pedicle screw of the preferred embodiment of the invention;

FIG. 9 is a block diagram of the C-shaped hemispherical ring of the universal pedicle screw of the preferred embodiment of the invention;

FIG. 10 is a block diagram of the central body of the universal pedicle screw of the preferred embodiment of the invention;

FIG. 11 is a cross-sectional view in the horizontal plane of the gimbal pedicle screw in a large offset angle swing configuration, in accordance with a preferred embodiment of the present invention;

in the figure: the screw base 1, U type groove 11, through-hole 12, inner recess 13, inclined to one side hole 14, riveting hole 15, internal thread 16, bone screw 2, nail body 21, C type hemisphere ring 22, installation department 23, toper step 24, toper recess 25, spacing step 26, upper step 27, midbody 3, C type groove 31, sphere 32, heavy groove 33.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings of the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

As shown in fig. 1-11, a universal pedicle screw comprises a screw base 1, a bone screw 2 and a middle body 3, wherein one end of the screw base 1 is provided with a U-shaped groove 11, the other end of the screw base is provided with a through hole 12, and one end of the through hole 12, which is far away from the U-shaped groove 11, is in an angle offset structure; the bone screw 2 comprises a nail body 21 and a pair of C-shaped hemispherical rings 22, wherein the C-shaped hemispherical rings 22 are detachably arranged at the head part of the nail body 21; the middle body 3 is arranged in the screw seat 1; the nail body 21 penetrates into the screw base 1 from the end of the screw base 1 where the through hole 12 is located and is matched with the C-shaped hemispherical ring 22 located in the through hole 12.

In order to realize the matching of the C-shaped hemispherical ring 22 and the nail body 21, a mounting part 23 is arranged at the top of the nail body 21, a tapered step 24 is arranged on the mounting part 23, and a tapered groove 25 matched with the tapered step 24 is arranged on the inner annular surface of the C-shaped hemispherical ring 22.

Specifically, the two C-shaped hemispherical rings 22 are relatively clamped on the outer side of the mounting portion 23, the tapered step 24 is clamped in the tapered groove 25, and the two C-shaped hemispherical rings 22 form a ball head structure.

In order to prevent the nail body 21 from falling out of the C-shaped hemispherical ring 22, the outer diameter of the upper end of the tapered step 24 is smaller than that of the lower end thereof.

Because the tapered groove 25 is matched with the tapered step 24, the inner diameter of the bottom of the tapered groove 25 is larger than that of the top of the tapered groove, and the tapered step 24 can be limited in the tapered groove 25, so that the nail body 21 is prevented from being separated from the C-shaped hemispherical ring 22, the nail body 21 is prevented from falling off the screw base 1, and the connection stability of the bone screw 2 and the screw base 1 is ensured.

And because the conical groove 25 and the conical step 24 are arranged, when the pedicle screw is assembled, the screw body 21 can directly support the two C-shaped hemispherical rings 22 when being assembled from the lower part of the C-shaped hemispherical ring 22, and the C-shaped hemispherical ring 22 can be automatically clamped outside the installation part 23 of the screw body 21 after the screw body 21 is installed in place, so that the quick assembly of the screw body 21 and the C-shaped hemispherical ring is realized, and the assembly efficiency of the pedicle screw is improved.

In order to facilitate the matching of the C-shaped hemispherical ring 22 and the nail body 21, an annular inner groove 13 is formed on the inner wall of the end part of the through hole 12 facing the U-shaped groove 11.

Preferably, the inner diameter of the through hole 12 at the inner groove 13 is larger than the outer diameter of the ball head formed by the two C-shaped hemispherical rings 22.

When the C-shaped hemispherical rings 22 are matched with the nail body 21, the two C-shaped hemispherical rings 22 can be placed in the inner groove 13 relatively, the installation part 23 of the nail body 21 penetrates from the bottom of the through hole 12, the two C-shaped hemispherical rings 22 are separated along with the penetration of the installation part 23, after the installation part 23 is positioned between the two C-shaped hemispherical rings 22, the conical grooves 25 of the two C-shaped hemispherical rings 22 and the conical steps 24 on the installation part 23 can be automatically meshed, the middle body 3 is installed on the screw seat 1, the riveting hole 15 in the screw seat 1 is riveted by using a riveting tool, the middle body 3 cannot be separated from the screw seat 1, and the assembly of the pedicle screw is completed.

In addition, the arrangement of the inner groove 13 can also facilitate the ball head composed of two C-shaped hemispherical rings 22 to follow the rotation of the nail body 21, and the ball head can also rotate in the angled hole 14 and can not fall off from the bottom of the angled hole 14.

In order to adjust the swing angle of the bone screw 2, an inclined angle hole 14 is formed at one end of the through hole 12, which is far away from the U-shaped groove 11.

In order to increase the pivot angle of the bone screw 2, the offset angle α of the axial direction of the offset hole 14 to the axial direction of the screw seat 1 is 7 ° to 23 °.

Preferably, the off-angle α is 15 °, i.e., a large off-angle that satisfies most clinical needs, and can correspondingly reduce the processing difficulty.

Specifically, the swing angle of the bone screw 2 towards the deflection angle direction can be increased to 50 degrees, and the swing angle towards the deflection angle direction can also reach 10 degrees, so that the special requirement on the pedicle screw with the large deflection angle is met.

The direction of the declination angle and the angle of the declination angle can be selected according to specific use cases. In the present embodiment, the off-angle is in the horizontal plane direction.

The two C-shaped hemispherical rings 22 can drive the nail body 21 to swing, and can also be used for connecting the nail body 21 with the screw seat 1, and for the convenience of installation of the C-shaped hemispherical rings 22, the nail body 21 and the screw seat 1, the inner diameter of the bottom of the inclined angle hole 14 is larger than the outer diameter of the installation part 23 and smaller than the outer diameter of a ball head formed by the two C-shaped hemispherical rings 22.

Specifically, the outer diameter of the mounting part 23 is smaller than the inner diameter of the eccentric hole 14, so that the nail body 21 can be conveniently loaded into the screw seat 1 from the bottom of the through hole 12, and the diameter of a ball head formed by the two C-shaped hemispherical rings 22 is larger than the inner diameter of the eccentric hole 14, so that the C-shaped hemispherical rings 22 are prevented from falling off from the bottom of the through hole 12, and the stable connection between the nail body 21 and the screw seat 1 is ensured.

In order to facilitate the installation of the connecting rod, the intermediate body 3 is of an annular structure, and a C-shaped groove 31 is formed in the top of the intermediate body.

When the pedicle screw is connected with the connecting rod, in order to ensure the matching between the pedicle screw and the connecting rod, a C-shaped groove 31 matched with the outer annular surface of the connecting rod is arranged, when the pedicle screw is installed, the connecting rod is placed in the C-shaped groove 31, and the stress of each matching part is ensured to be uniform.

In order to realize the matching of the C-shaped hemispherical ring 22 and the middle body 3, a limiting step 26 is arranged on the outer annular surface of the top of the C-shaped hemispherical ring 22, and the limiting step 26 is matched with the limiting step 26 at the bottom of the middle body 3.

Specifically, the bottom of the inner annular surface of the middle body 3 is provided with a spherical surface 32, the inner diameter of the top end of the spherical surface 32 is smaller than that of the bottom end thereof, the two C-shaped hemispherical rings 22 are arranged outside the mounting part 23 of the nail body 21, and the top of the mounting part 23 and the top of the C-shaped hemispherical ring 22 extend into the middle body 3 to be matched with the spherical surface 32.

Specifically, an upper step 27 is arranged on the outer ring at the top of the mounting portion 23, four steps formed by the upper surface of the mounting portion 23, the upper step 27, the upper surface of the C-shaped hemispherical ring 22 and the limiting step 26 are located in the same spherical surface 32 at the bottom of the intermediate body 3, and the position of the intermediate body 3 is limited during assembly, so that a sunk groove 33 on the side surface of the intermediate body 3 is located at a riveting position.

In clinical operation, when the pedicle screw is locked, the middle body 3 can be ensured to firmly hold the bone screw 2 due to the arrangement of the four steps formed by the upper surface of the mounting part 23, the upper step 27, the upper surface of the C-shaped hemispherical ring 22 and the limiting step 26, so that the bone screw 2 has enough strength to support the biological load of the vertebral body, and the loss of the height of the vertebral body caused by the untight locking of the bone screw 2 is prevented.

In order to prevent the middle body 3 from falling off from the screw base 1, riveting holes 15 are formed in the outer walls of the two sides of the screw base 1, and sinking grooves 33 corresponding to the riveting holes 15 are formed in the outer walls of the two sides of the middle body 3.

Preferably, the staking hole 15 is a blind hole.

Specifically, the riveting hole 15 in the screw seat 1 is punched through the riveting tool, so that the inner wall of the riveting hole 15 is deformed inwards to form an inner protrusion, and the inner protrusion is matched in the sinking groove 33 of the intermediate body 3, so that the middle part is prevented from being separated.

In order to facilitate the fixing of the connecting rod, the inner walls of the two sides of the U-shaped groove 11 are concave cambered surfaces, and the inner walls are provided with internal threads 16.

The connecting rod is clamped into the U-shaped groove 11 of the screw base 1 and placed in the C-shaped groove 31 of the intermediate body 3, and then screwed into the top of the U-shaped groove 11 by means of a locking plug screw, which cooperates with the internal thread 16, thereby fixing the connecting rod.

When the pedicle screw is assembled, two C-shaped hemispherical rings 22 are firstly sequentially arranged in the inner groove 13 of the screw seat 1, then the mounting part 23 of the nail body 21 is arranged in the screw seat 1 from the bottom of the through hole 12 to the top and penetrates between the two C-shaped hemispherical rings 22, the C-shaped hemispherical rings 22 are clamped on the periphery of the mounting part 23, so that the tapered groove 25 of the C-shaped hemispherical ring 22 is well matched with the tapered step 24 on the mounting part 23, the middle body 3 is arranged above the screw seat 1, the bottom of the middle body 3 is clamped on the step at the top of the C-shaped hemispherical ring 22, after the assembly is confirmed to be correct, the riveting hole 15 in the screw seat 1 is punched by adopting a riveting tool, the inner wall of the riveting hole 15 deforms to form an inner bulge, and the inner bulge is matched in the sinking groove 33 of the intermediate body 3 to prevent the intermediate body 3 from being separated from the screw seat 1, so that the whole pedicle screw can be assembled.

The invention has simple integral structure and convenient assembly, the diameter of the nail body 21 can be randomly selected according to the requirement without size limitation, the swing angle of the bone screw 2 can be increased through the design of the deflection angle hole 14, the direction and the size of the swing angle can be selected according to the requirement, when in use, all parts are well matched, the stress is uniform, the structure is stable, and the invention is suitable for the use occasions with special requirements such as sacroiliac joint fixation surgery and the like.

In light of the foregoing description of the preferred embodiment of the present invention, many modifications and variations will be apparent to those skilled in the art without departing from the spirit and scope of the invention. The technical scope of the present invention is not limited to the content of the specification, and must be determined according to the scope of the claims.

Claims

1. A universal pedicle screw is characterized by comprising

The screw comprises a screw seat (1), wherein one end of the screw seat (1) is provided with a U-shaped groove (11), the other end of the screw seat is provided with a through hole (12), and one end, far away from the U-shaped groove (11), of the through hole (12) is of a deflection angle structure;

the bone screw (2), the said bone screw (2) includes the shank (21) and a pair of C-type semispherical rings (22), the said C-type semispherical ring (22) is installed on the head of the said shank (21) removably;

the middle body (3), the middle body (3) is arranged in the screw seat (1);

the nail body (21) penetrates into the screw base (1) from the end of the through hole (12) of the screw base (1) and is matched with a C-shaped hemispherical ring (22) positioned in the through hole (12).

2. The universal pedicle screw according to claim 1, wherein a mounting portion (23) is arranged at the top of the screw body (21), a tapered step (24) is arranged on the mounting portion (23), and a tapered groove (25) matched with the tapered step (24) is arranged on the inner annular surface of the C-shaped hemispherical ring (22).

3. The universal pedicle screw according to claim 2, wherein the outer diameter of the upper end of the tapered step (24) is smaller than the outer diameter of the lower end thereof.

4. The universal pedicle screw according to claim 2, wherein an annular inner groove (13) is formed in the inner wall of the end portion, facing the U-shaped groove (11), of the through hole (12), and an inclined angle hole (14) is formed at the end, far away from the U-shaped groove (11).

5. The universal pedicle screw according to claim 4, wherein the angle of the offset hole (14) in the axial direction to the screw seat (1) is 7-23 °.

6. The universal pedicle screw according to claim 4, wherein the bottom inner diameter of the angled hole (14) is larger than the outer diameter of the mounting portion (23) and smaller than the outer diameter of a ball head consisting of two C-shaped hemispherical rings (22).

7. The universal pedicle screw according to claim 1, wherein the intermediate body (3) is of an annular structure and is provided with a C-shaped groove (31) at the top.

8. The universal pedicle screw according to claim 1, wherein a limiting step (26) is arranged on the outer annular surface of the top of the C-shaped hemispherical ring (22), and the limiting step (26) is matched with the bottom of the middle body (3).

9. The universal pedicle screw according to claim 1, wherein riveting holes (15) are formed in the outer walls of the two sides of the screw base (1), and sunk grooves (33) corresponding to the riveting holes (15) are formed in the outer walls of the two sides of the middle body (3).

10. The universal pedicle screw according to claim 1, wherein the inner walls of the U-shaped groove (11) on both sides are concave cambered surfaces, and the inner walls are provided with internal threads (16).