KR102132188B1 - Pedicle screw assembly capable of largely forming an angle at which a pedicle screw is bent - Google Patents

Abstract

The present invention is composed of a spine screw body and a head part in a separate type rather than an integral form, and the spine screw body is formed by maximally forming an angle that can be bent from the head part, such as a lumbar or cervical spine. Even if the vertebral screw body is operated on the vertebrae in different directions and at different angles, the direction and angle of the head part are aligned in line with each other and a rod is mounted on it, making it easy to perform pedicle screw manipulation in the lumbar spine as well as in the cervical spine. It relates to a spinal screw assembly capable of largely forming an angle at which the spinal screw is bent.

Description

Spine screw assembly capable of largely forming the angle at which the vertebral screw is bent{PEDICLE SCREW ASSEMBLY CAPABLE OF LARGELY FORMING AN ANGLE AT WHICH A PEDICLE SCREW IS BENT}

The present invention relates to a vertebral screw assembly, and more specifically, a vertebral screw that facilitates fastening of a rod can be largely formed by allowing the head of the vertebral screw to bend after the vertebral screw is operated on the vertebra. It relates to a spinal screw assembly.

There is a disc between the vertebrae and the adjacent vertebrae, the outer side of which is protected with ligaments, and the nucleus inside the disc.

Here, the disc functions as a joint and plays a very important role in minimizing the impact on the spine as the position and shape of the nucleus pulposus changes according to the movement of the spine.

Most of the nucleus pulposus is made of water (water), and as it ages, the amount of water gradually decreases and the disc loses its buffering function.

Due to this, when excessive pressure is applied to the fiber, pain occurs, and when it is further advanced, the fiber is severely stretched or ruptured, and the nerve root located at the back is pressed to cause pain in the pelvis, legs, and the like.

Afterwards, various side effects have occurred, such as gradual narrowing of the spine or spinal deformity as the vertebrae descend.

For this reason, when performing surgery to remove severely distorted or upper discs, measures should be taken to maintain the vertebral spacing and prevent the spine from deforming or shaking.

To this end, during the spinal procedure, the operator removes the disc of the damaged portion so that the damaged portion of the vertebra is not pressed or pressed, and the disc is removed by filling the artificial aid (cage) made of hollow metal or plastic material with a piece of bone. To insert.

Thereafter, after inserting and fixing a pedicle screw into the vertebra of the upper and lower parts of the damaged disc, a method is performed in which bone fusion is normally performed by connecting a rod to the pedicle screw to secure a distance between the vertebrae.

Patent No. 10-0994184 (spine screw module) was invented in view of the above, one end of the body has a tool groove formed head portion, and the other end of the body is a pedicle screw formed with a screw inserted into the pedicle. and; A U-shaped storage groove having a predetermined depth for receiving a rod is formed on the upper body, and a female screw portion is formed along the inner circumferential surface of the storage groove. , A rod fixing part having a connector formed to be inserted into the head part to connect with the pedicle screw; An elastic washer inserted into the connector of the rod fixing part through the storage groove; And a bolt in which a male screw portion is formed along the outer diameter of the body so as to be fastened with the female screw portion, and a wrench groove is formed in the center of the body. The elastic washers are configured to include a rod in the storage groove and secure the rod. When tightened, the rod is in close contact with the rod and the pedicle screw and the rod fixing portion at the same time, the rod and the pedicle screw module fixed to the rod and the pedicle screw module is configured to have a predetermined range of fluidity It is characterized by.

In addition, the registered patent No. 10-0994184 is a pedicle screw module according to the prior art consists of a threaded part inserted into the pedicle and a head part mounted with a rod, and a rod made of a non-elastic straight medical titanium material is used. Therefore, it solved a problem that could lead to spinal diseases.

However, even though the patented Patent No. 10-0994184 has a separate screw part inserted into the pedicle and a head part mounted with a rod, the screw part is flexible within a predetermined range in order to solve the vertebral disease that may occur in the existing integral type. Although it can move, there is a problem that it is difficult to apply when the rod is easily mounted when the head part fastened to the pedicle screw is largely bent due to large formation of rodosis like the cervical vertebra.

Patent No. 10-0994184 (Spine module screw)

In the conventional spinal screw, in a spinal procedure in which rodosis is largely formed, such as the cervical or lumbar spine, the angle at which the screw body and the head portion are bent is so limited that it is not easy to mount the rod on the head, and even if it is installed, It does not give natural movement, so it is easy to cause side effects.

The present invention was invented to improve the problems as described above, and the spinal screw body and the head portion are configured as a separate type rather than an integral type, and the lumbar or cervical spine is formed by maximally forming an angle at which the spinal screw body can be bent from the head portion. Even if the vertebral screw body is operated on the vertebra in different directions and at different angles in a spinal procedure in which a large amount of rodosis is formed, the lumbar spine is aligned by aligning the direction and angle of the head in line with each other and mounting a rod on it. In addition, it is intended to provide a spinal screw assembly capable of largely forming an angle at which a spinal screw is bent to facilitate the operation of a spinal screw in the cervical spine.

To this end, the present invention is to provide a spinal screw assembly having a structural feature that allows the spinal screw body coupled to the head portion to be bent at a large angle relative to the central axis of the head portion.

In order to achieve the above object, the present invention is a screw body including a body fixed to the vertebra and a joint head provided at an end of the body; A head portion having an accommodation space on which an upper surface is opened and on which the joint head and the rod are seated; Supporting the circumference of the lower surface of the joint head from the inside of the head portion, the elliptical shape is formed to be left and right in the center so that the body connected to the lower portion of the joint head can be bent to both left and right within a predetermined angle range. A joint head support having a through hole; And a washer located inside the head portion and positioned above the joint head support portion to support a portion of the outer circumferential surface of the rod, wherein the joint head is in close contact with the right side based on the virtual central axis of the joint head support portion. When the lower part of the body is bent to the left, the maximum angle is bent, and when the joint head is bent to the left with respect to the virtual central axis, when the lower part of the body is bent to the right, the spinal screw is bent. Provided is a spinal screw assembly capable of forming a large angle.

Here, the head portion is formed to penetrate through the top and bottom, the bottom surface has a locking jaw formed inwardly, the joint head support portion is provided on the head receiving portion for receiving the joint head, and the head receiving portion and projecting outward It has a formed protrusion, the joint head support is fitted downward from the top of the head, the lower portion of the joint head support is exposed partially below the head, the projection is seated and supported on the locking jaw, and the washer is a joint head support It is located above the protrusion and has a space formed through the center so that the joint head on the top of the body can rotate when the body is bent to both left and right sides.

In addition, the joint head support portion accommodates the joint head, and the inner circumference is formed in a curved surface to correspond to the spherical surface of the joint head, and the upper part of which the upper surface of the joint head is exposed is formed through a long ellipse to the left and right, and the body penetrates. The lower portion of the joint head is formed through a long oval to the left and right while being smaller in size than the through hole of the ellipse formed on the upper portion.

In addition, a width corresponding to a direction orthogonal to the left and right longitudinal directions of the elliptical through-hole formed on the upper portion of the joint head exposed is corresponding to the diameter of the joint head.

Here, the joint head support portion, the head receiving portion for receiving the joint head and exposed below the head portion; It is formed on the lower portion of the head accommodating portion, the lower through-hole having an elliptical shape, which is elongated to the left and right sides of the body; It is provided on the upper portion of the head accommodating portion is formed to protrude outwardly and is seated and supported on a locking jaw formed inwardly from the bottom surface of the head portion; And an upper through-hole formed in both left and right sides in a length and width greater than a portion of the lower through-hole in the center of the protrusion, and a surface connecting the lower through-hole with the upper through-hole corresponds to the spherical surface of the joint head. It is formed in a curved surface so that the joint head can be moved to both left and right sides in a certain range along the left and right longitudinal directions.

In addition, the joint head support portion, the head receiving portion receiving the joint head and exposed below the head portion; It is formed on the lower portion of the head accommodating portion, the lower through-hole having an elliptical shape, which is elongated to the left and right sides of the body; It is provided on the upper portion of the head accommodating portion is formed to protrude outwardly and is seated and supported on a locking jaw formed inwardly from the bottom surface of the head portion; And the lower through-hole in the center of the protrusion has the same length formed in both the left and right sides, but having an upper through-hole that is formed to have a certain width larger, and the surface connecting the lower through-hole with the upper through-hole is a joint head. It is formed in a curved surface to correspond to a spherical surface, and the joint head can be moved left and right in a certain range along the left and right longitudinal directions.

Furthermore, both the left and right sides of the head accommodating portion are incised to correspond to the widths of the elongated elliptical lower through-holes on both the left and right sides and bent at the maximum angle when the body is bent to the left while the joint head is in close contact to the right. , When the joint head is bent to the right in the state in close contact with the left side, it forms an additional space that can be bent at a maximum angle.

According to the present invention having the above configuration, the following effects can be achieved.

First, according to the present invention, the joint head of the spine screw can be rotated and left and right to form a free space to be able to move within a certain range, so that the screw body can be largely bent at the head portion, such as a lumbar or cervical spine. When the screw is fixed in the spine where (Lordosis) is largely formed, the head part can be aligned neatly, and the rod can be easily mounted and fixed separately from the state where each screw is stuck in the spine.

As a result, the operator can be provided with the convenience of the procedure, and the patient can minimize the side effects after the procedure.

Specifically, in the present invention, the joint head is bent at a maximum angle when the lower portion of the spinal screw body is bent to the left in a state in which the joint head is in close contact with respect to the virtual central axis of the joint head support portion, and the joint head is an imaginary center of the joint head support portion. When the lower part of the vertebral screw body is bent to the right in a state of close contact with respect to the axis, the screw is inserted into the vertebrae where the rhodosis is largely formed, such as the lumbar spine as well as the cervical spine, and then fixed with a rod It can be useful when ordering.

1 is a perspective view, a front view and a cross-sectional view of a spinal screw assembly according to an embodiment of the present invention.
2 is an exploded perspective view of a spinal screw assembly according to an embodiment of the present invention.
3 is an exemplary view showing a state in which the body of the spinal screw assembly according to an embodiment of the present invention is bent.
4 is an exemplary view showing a state in which the body of the spinal screw assembly according to another embodiment of the present invention is bent.
5 is an exemplary view showing a state in which the screw body of the spinal screw assembly according to an embodiment of the present invention is located at the center of the joint head support.
Figure 6 is an exemplary view showing a state in which the screw body of the spinal screw assembly according to an embodiment of the present invention is in close contact with either side of the joint head support.
7 is an exemplary view showing a state in which the body of the spinal screw assembly is bent to one side in FIG. 6.
8 is a perspective view and a cross-sectional view showing a configuration of a joint head support included in a spinal screw assembly according to an embodiment of the present invention.
9 is an exemplary view showing a state in which the body of the spinal screw assembly is bent to one side according to another embodiment of the present invention.
10 is a perspective view and a cross-sectional view showing a configuration of a joint head support included in a spinal screw assembly according to another embodiment of the present invention.

Advantages and features of the present invention, and methods for achieving them will be clarified with reference to embodiments described below in detail together with the accompanying drawings.

However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms.

This embodiment in the present specification is to provide a complete disclosure of the present invention, and to fully inform the scope of the invention to those skilled in the art to which the present invention pertains.

And the present invention is only defined by the scope of the claims.

Thus, in some embodiments, well-known components, well-known operations, and well-known techniques are not specifically described to avoid obscuring the present invention.

In addition, the same reference numerals throughout the specification refer to the same components, and the terms used (referred to) in this specification are for describing the embodiments and are not intended to limit the present invention.

In the present specification, the singular form also includes the plural form unless specifically stated in the phrase, and the components and operations referred to as'comprising (or, provided)' do not exclude the presence or addition of one or more other components and operations. .

Unless otherwise defined, all terms (including technical and scientific terms) used in the present specification may be used as meanings commonly understood by those skilled in the art to which the present invention pertains.

In addition, terms defined in the commonly used dictionary are not ideally or excessively interpreted unless defined.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

1 and 2, the spinal screw assembly capable of largely forming an angle at which the spinal screw is bent includes a screw body 100, a head part 200, a joint head support part 300, and a washer 400. Includes.

The screw body 100 includes a body 110 fixed to the vertebrae and a joint head 120 provided at an end of the body 110.

The head part 200 includes an accommodation space 201 on which an upper surface is opened and a joint head 120 and a rod (not shown) are seated.

The joint head support part 300 supports and supports the circumference of the lower surface of the joint head 120 from the inside of the head part 200, and the body 110 connected to the lower part of the joint head 120 is within a predetermined angle range. It is provided with elliptical through holes 315 and 325 formed in both the left and right sides in the center so as to be bent to both the left and right sides.

The oval through holes 315 and 325 are composed of a lower through hole 315 and an upper through hole 325, which will be described in detail with reference to FIGS. 8 and 10 below. The body 110 penetrates the lower through hole 315.

Referring to FIG. 2, first, the joint head support portion 300 is inserted into the head portion 200, and the screw body 100 is coupled through the joint head support portion 300. And the washer 400 is fitted thereon.

The washer 400 is located on the upper portion of the joint head support portion 300 from the inside of the head portion 200 and supports the portion of the outer circumferential surface of the rod.

Referring to Figures 1 and 2, the washer 400 is coupled to the last, and then press the pressing part 210 on both the left and right sides of the head part 200 by using a separate mechanism to be pressed inward and inward. The pressed portion is pushed into the grooves 410 on both the left and right sides of the washer 400, so that the washer 400 can be securely fixed without falling out.

6(c) and 7(c), the joint head 120 is based on the virtual central axis VL of the joint head support portion 300 to the right in the joint head support portion 300. When the lower part of the body 110 is bent to the left in a close state, it is bent at the maximum angle which is the first angle θ1.

In addition, although not shown in the drawing, the first angle (θ1) when the lower portion of the body 110 is bent to the right in the state in which the joint head 120 is closely adhered to the left based on the virtual central axis VL. Bend at an angle.

This point is important to differentiate it from the conventional technology. In the conventional spinal screw, although the head portion and the screw body are formed separately, the joint head of the screw body is not a structure that can be moved to the left or right, but only rotates on the spot. Because it can, the screw body is not a structure that can be bent at a large angle.

However, according to the present invention, the joint head 120 moves close to the right or left side within the joint head support portion 300, and then, when the body 110 is bent to the left or right, the joint head support portion 300 ) Can be bent at an angle as large as the length of the oval through holes 315 and 325 formed in the center of the ).

Referring to FIG. 5, it can be seen that the joint head 120 is centrally located within the joint head support portion 300.

Referring to FIG. 6, unlike in FIG. 5, it can be seen that the joint head 120 and the body 110 are moved to the right based on the virtual central axis VL of the joint head support portion 300 to be in close contact. And referring to FIG. 7, it can be seen that the body 110 is bent to the left by a first angle θ1. In order to bend the body 110 by a first angle θ1 to the left, the lower through hole 315 through which the body 110 penetrates and the upper through hole 325 through which the joint head 120 is exposed are left and right. It should be an oval that is formed long.

9(c) shows another embodiment of the present invention, in this case, it may be bent to a second angle θ2, which is an angle greater than the first angle θ1. Detailed description of this will be described below with reference to the drawings.

The head part 200 is formed to penetrate through the top and bottom, and has a locking jaw 220 bent inward on the bottom surface.

The joint head support portion 300 includes a bowl-shaped head accommodating portion 310 accommodating the joint head 120, and a protruding portion 320 provided on an upper portion of the head accommodating portion 310 and protruding outward.

The joint headrest 300 is fitted from the top to the bottom of the head portion 200, the lower portion of the joint headrest 300 is exposed partly below the head portion 200, and the protrusion 320 is a locking jaw ( 220).

The washer 400 is located above the protruding part 320 of the joint head support part 300 and the center so that the joint head 120 above the body 110 can rotate when the body 110 is bent to both left and right sides. It is provided with a space to be formed through.

3 and 4, if there is no space formed through the center of the washer 400, the joint head 120 provided on the upper part of the body 110 hits the washer 400, so that the body 110 is left, You will not be able to bend to the right.

6 to 8, the joint head support portion 300 accommodates the joint head 120 and has an inner circumference formed as a curved surface 330 to correspond to the spherical surface of the joint head 120. When the inner circumference is formed by the curved surface 330, the joint head 120 can rotate naturally along the curved surface 330 when it rotates.

Referring to FIG. 8, the upper portion of the joint head 120 where the upper surface is exposed is formed with an upper elliptical hole 325 in a long oval shape to the left and right, and a lower portion of the joint head 120 through which the body 110 penetrates. The lower through-hole 315 is formed in an elliptical shape to the left and right while being smaller than the elliptical through-hole 325 formed on the upper portion.

The left and right lengths of the upper through hole 325 form the first ellipse length L1, and the left and right lengths of the lower through hole 315 form the second ellipse length L2. L1> L2.

When the lower through hole 315 is smaller than the upper through hole 325, the joint head 120 will not be caught and will not fall down.

The width orthogonal to the longitudinal direction L1 of the upper through hole 325 forms a first width W1, and the width orthogonal to the longitudinal direction L2 of the lower through hole 315 is the second width W2. To form. W1> W2.

In addition, recessed portions 313 that are recessed are formed in portions where the second width W2 is formed on both sides based on the center of the lower through hole 315. The body 110 is rotated and bent in the longitudinal direction, but in order to move naturally without being too stiff when rotating, the concave portions 313 are formed on both sides where the second width W2 is formed to make a little free space. It is necessary to put.

The width W1 corresponding to a direction orthogonal to the left and right length L1 direction of the upper through hole 325 of the ellipse formed on the upper portion of the joint head 120 is exposed to the diameter of the joint head 120 It is desirable to respond.

5 and 6, the diameter and width W1 of the joint head 120 are formed the same.

Referring to FIG. 8, the joint head support portion 300 accommodates the joint head 120 and is formed under the head receiving portion 310 exposed under the head portion 200 and the head receiving portion 310. It is provided on the upper side of the head receiving portion 310, the lower through hole 315 of an elliptical shape on both the left and right sides through which the body 110 penetrates, and is formed to protrude outward from the bottom surface of the head portion 200 to the inside. The upper through-hole formed in both the left and right sides of the projection 320 and the lower through-hole 315 in the center of the protrusion 320 that are seated and supported on the bent locking jaw 220 are formed to be larger than the lower through-hole 315. 325).

The surface connecting the lower through hole 315 and the upper through hole 325 is formed of a curved surface 330 to correspond to the spherical surface of the joint head 120, and the joint head 120 is constant along the left and right longitudinal directions. You can move left and right in the range.

9 and 10, another embodiment of the present invention is shown.

The joint head support part 300 accommodates the joint head 120 and is formed under the head receiving part 310 exposed under the head part 200 and the head receiving part 310 and the body 110 is provided. An elliptical lower through hole 315 that is elongated on both sides of the left and right sides, and is provided on an upper portion of the head accommodating part 310 and protruding outwardly to be formed to be bent inward from the bottom surface of the head part 200. ), the length of the lower through hole 315 and the left and right sides (L1) formed in the center of the protrusion 320 and the protrusion 320 supported on the same side is the same, but the upper through hole is formed to have a larger width (325).

7 and 8, the difference between the upper through-hole 325 and the lower through-hole 315 is equal to L1. The lower through-hole 315 is also formed with the same length (L1) as the upper through-hole 325, so that the body 110 can be bent to both left and right sides.

As a result, the second angle θ2 in FIG. 9(c)> the first angle θ1 in FIG. 7(c).

However, a width orthogonal to the longitudinal direction L1 of the upper through hole 325 forms a first width W1, and a width orthogonal to the longitudinal direction L1 of the lower through hole 315 is a second width W2. ). W1> W2. Of course, the width of the joint head 120 must be different in order to support it.

The surface connecting the lower through hole 315 and the upper through hole 325 is formed of a curved surface 330 to correspond to the spherical surface of the joint head 120, and the joint head 120 is constant along the left and right longitudinal directions. You can move left and right in the range.

Referring to FIG. 10, the left and right sides of the head receiving portion 310 are incised as long as they correspond to the widths of the elongated elliptical lower through holes 315 on both the left and right sides, and the joint head 120 is closely adhered to the right side. When the body is bent to the left in the state, it is bent at the maximum angle, and when the joint head 120 is bent to the left, the body is bent to the right to form an additional space 340 that can be bent at the maximum angle.

In summary, the lengths of the upper through hole 325 and the lower through hole 315 are the same as L1 even though the left and right side surfaces of the head receiving portion 310 are not cut to form additional spaces 340. The angle in which the body 110 is bent is formed slightly larger than in the embodiment 8.

Here, when the left and right sides of the head accommodating part 310 are incised to form an additional space 340 having a square shape, when the body 110 is bent in both left and right directions, the additional space 340 is bent. You can lose it, so it is bent at the maximum angle.

In the present invention, the joint head is bent at a maximum angle when the lower portion of the spinal screw body is bent to the left in a state in which it is in close contact with respect to the virtual central axis of the joint head support, and the joint head is based on the virtual central axis of the joint head support. When the lower part of the vertebral screw body is bent to the right in the state in close contact with the left side, it can be bent at the maximum angle. Could be used.

Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art to which the present invention pertains can describe the present invention in other specific forms without changing its technical spirit or essential features, as described above. It should be understood that the embodiments are illustrative in all respects and not restrictive.

And, the scope of the present invention is specified by the claims, which will be described later, rather than by the detailed description, and all the changed or modified forms derived from the meaning and scope of the claims and their equivalent concepts are included in the scope of the present invention. It should be interpreted as.

100...screw body
110... body
120...joint head
200...head
201...accommodation space
210...press
220...
300...joint head support
310...head receiving part
313...
315...lower through hole
320... Projection
325 ... upper through hole
330...surface
340... additional space
400...washer
410... Home
VL...virtual central axis
θ1...first angle
θ2...second angle
W1...first width
W2...second width
L1...first ellipse length
L2...second ellipse length

Claims (7)

A screw body including a body fixed to a vertebra and a joint head provided at an end of the body;
A head portion having an accommodation space on which an upper surface is opened and on which the joint head and the rod are seated;
Supporting the circumference of the lower surface of the joint head from the inside of the head portion, the elliptical penetrating through the left and right sides in the center so that the body connected to the lower portion of the joint head can be bent to both left and right within a predetermined angle range. A joint head support having a ball; And
It is located on the upper portion of the joint head support from the inside of the head portion includes a washer for supporting a portion of the outer peripheral surface of the rod,
The joint head is bent at a maximum angle when the lower part of the body is bent to the left in the state in which the joint head is in close contact with respect to the right with respect to the virtual central axis, and in the state in which the joint head is in close contact with the left in relation to the virtual central axis. When the lower part of the body is bent to the right, it is bent at the maximum angle,
The joint head support portion,
A head accommodating portion accommodating the joint head and exposed under the head portion;
An elliptical lower through hole formed in the lower portion of the head accommodating portion, through which the body penetrates, and formed in a length of L1 and perpendicular to the length (L1) direction to form a second width (W2);
It is provided on the upper portion of the head accommodating portion is formed to protrude outwardly to be seated and supported on the locking jaw formed inwardly from the bottom surface of the head portion; And
The length (L1) formed in both the left and right sides of the lower through hole in the center of the protrusion is the same, but the width orthogonal to the length (L1) direction is a part of the first width (W1) that is partly larger than the second width (W2) of the above ) Is provided with an upper through hole forming
The surface connecting the lower through hole and the upper through hole is formed in a curved surface to correspond to the spherical surface of the joint head, and the joint head can be moved to both left and right sides in a certain range along the left and right longitudinal directions,
Both the left and right sides of the head receiving portion are incised to correspond to the width of the oval bottom through-hole, so that when the joint head is in close contact with the right side, the body is bent at the maximum angle when bent to the left, and the joint head is in close contact with the left side. Spine screw assembly that can form a large angle of the spine screw, characterized in that to form an additional space to bend at the maximum angle when the body is bent to the right in the state.
The method according to claim 1,
The head portion is formed to penetrate through the top and bottom, the bottom surface is provided with a locking jaw formed inwardly,
The joint head support portion includes a head receiving portion for accommodating the joint head, and a projection provided above the head receiving portion and protruding outwardly,
The joint head support portion is fitted from above to the bottom of the head portion, the lower portion of the joint head support portion is exposed to a certain portion below the head portion, the protrusion is seated on the locking jaw, supported,
The washer is located above the projecting portion of the joint head support, and the spine screw is bent, characterized in that it has a space formed through the center so that the joint head at the top of the body can rotate when the body is bent to both left and right sides. Spine screw assembly that can form a large angle.
The method according to claim 1,
The joint head support portion,
The inner periphery is formed in a curved surface to accommodate the joint head and corresponds to the spherical surface of the joint head, and the upper portion of the joint head is exposed through an elliptical shape, and the lower portion of the joint head through which the body penetrates is an ellipse formed on the upper portion. A spinal screw assembly capable of forming a large angle at which a spinal screw is bent, characterized in that it is formed through an oval having a smaller size than a ball.
The method according to claim 3,
A width corresponding to a direction orthogonal to the left and right longitudinal directions of the through hole of the ellipse formed on the upper portion of the joint head exposed to form a large angle at which the spinal screw is bent, characterized in that it corresponds to the diameter of the joint head. Spine screw assembly that can be done.
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