KR20220073976A - Vertebral fixation apparatus - Google Patents

Abstract

In the spinal fixation device for fixing the vertebrae facing each other, there is disclosed a spinal fixation device having a rod for fixing the vertebrae to each other.
The disclosed spinal fixation device includes: a spinal fixation screw having a body part formed with a first fastening part to be inserted and fastened to a spine, and a head part formed at one end of the body part; A hollow body having a first fastening part formed therein, a mounting part provided on one side of the body to rotatably mount the head, and a channel hole penetrating through the X-axis with respect to the Y-axis of the spine fixing screw is formed in the body. a receiving member; and a nut member that is formed with a second fastening part screw-coupled to the first fastening part and is positioned above the head part and fixed therein;
The first fastening portion is formed to protrude in the insertion direction, the first bending preventing portion to prevent the receiving member from being bent by the pressure applied when the nut member is inserted; and a second bending prevention part formed in a position symmetrical to the left and right with respect to the first bending prevention part and the axis to prevent the receiving member from bending, and the second fastening part corresponds to the first bending prevention part and is inserted when fastening. a first corresponding bending prevention unit formed with a groove; and a second anti-bending portion protruding to be inserted when fastening in correspondence with the second anti-bending portion to be positioned symmetrically on the left and right with respect to the first anti-bending portion and the axis.

Description

Spinal fixation device {VERTEBRAL FIXATION APPARATUS}

The present invention relates to a spinal fixation device, and more particularly, to a spinal fixation device that prevents a spinal fixation screw from being bent by a pressing force when it is fastened and maintains a continuous fixation force.

The spine plays an important role in supporting the body and maintaining equilibrium, as well as protecting the spinal cord. Various spinal diseases such as disc herniation, spondylolisthesis, degenerative spondylolisthesis, and spondylolisthesis, which cause pain in these spinal regions, can occur, which can bring inconvenience to daily life.

Recently, if possible, surgery is not performed or if surgery is required, it is treated with minimal incision. In other words, stenosis accompanied by instability, severe lumbar spondylolisthesis in which the vertebrae fall forward, or relapse after disc surgery may require spinal fixation.

Spinal fixation surgery removes all the diseased discs between the vertebrae and neighboring bones, inserts a disc-shaped support called a cage between them, and stabilizes the unstable vertebrae by fixing the spine with a spinal fixation device to prevent problems from occurring again. It is a fundamental way to treat.

In the conventional spinal fixation device, when the head part of the spinal fixation screw in the receiving member rotates at a predetermined angle with the body part and is fixed, the load by the rod directly affects the spinal fixation screw, so that the surface that engages the head part is may be worn out. In addition, the fixing force, which is a problem in which the head of the spine fixing screw is easily separated from the receiving member, is weak. In addition, the residue generated when the rod guide member is cut from the accommodating member in the procedure step may cause inflammation in the body tissue, thereby causing side effects of the procedure. In addition, since the fractured surface of the cut receiving member is uneven, the portion protrudes after the operation, and patients may feel discomfort in their daily life.

Registered Patent Publication No. 10-0324698 (2002.02.01.) Registered Patent Publication No. 10-0589728 (2006.06.07.) Korean Patent Publication No. 10-2001-0047359 (June 15, 2001)

The present invention has been devised in view of the above points, and an object of the present invention is to provide a spinal fixation device that prevents the spinal fixation screw from being separated from the receiving member during rotation and maintains the continuous fixation force of the spinal fixation screw after surgery. have.

In order to achieve the above object, the spinal fixation device of the present invention is provided with a body portion in which a vertebral fastening portion which is a screw thread to be inserted and fastened to the spine is fixed, and a head portion formed at one end of the body portion is formed. with a spinal fixation screw; A hollow body having a first fastening portion formed therein, and a mounting portion provided on one side of the main body to rotatably mount the head, the main body penetrates through the X-axis with respect to the Y-axis of the spinal fixation screw a receiving member in which a channel hole is formed; and a nut member having a hollow side surface formed with a second fastening part screw-coupled to the first fastening part and positioned above the head part for fixing.

a first bending preventing part formed to protrude in the insertion direction of the first fastening part to prevent the accommodating member from being bent by the pressure applied when the nut member is inserted; and a second bending prevention part formed in a position symmetrical to the left and right with respect to the first bending prevention part and the axis to prevent the accommodating member from bending, wherein the second fastening part corresponds to the first bending prevention part, a first corresponding bending prevention part formed with a groove to be inserted during fastening; and a second anti-bending portion protrudingly formed to correspond to the second anti-bending portion and inserted during fastening to be positioned symmetrically with respect to the first anti-bending portion and the axis.

The first fastening portion consists of a first inclined portion positioned on the upper side of the screw thread and having an inclination angle, and a second inclined portion positioned adjacent to the lower surface of the screw thread and positioned adjacent to each other to have a smaller inclination angle than the first inclined portion, The second fastening part consists of a first corresponding inclined part positioned on the lower side of the screw thread and inserted corresponding to the first inclined part, and a second corresponding inclined part positioned on the upper surface of the screw thread and inserted corresponding to the second inclined part. , As the inclination angle of the first inclined portion and the first corresponding inclined portion is greater than that of the second inclined portion and the second corresponding inclined portion, initial fastening may be facilitated and deformation may be minimized.

Each of the first fastening part and the second fastening part may satisfy Conditional Expression 1 below.

<Condition 1>

Here, S ₁ is the inclination angle (Degree) of the first inclined part or the first corresponding inclined part inclined along the -x and -y axes with respect to the X axis, and S ₂ is the inclination of the second inclined part or the second corresponding inclined part. An angle (Degree), and P ₁ means a pitch between the first bending prevention part or the first corresponding bending prevention part, and L ₁ is the inner side surface of the first bending prevention part of the accommodating member or the nut member Means the length (mm) of the section of the outer side of the first corresponding bending prevention part. And D ₁ means the outer diameter (mm) of the receiving member inner diameter groove, D ₂ means the outer diameter (mm) of the nut member.

The receiving member may further include a cutout having grooves formed on the outer circumferential surface and the inner circumferential surface of the main body to be cutable along the X-axis with respect to the Y-axis.

The cut part consists of an outer cut part and an inner cut part between the main body based on the X-axis to be cut of the main body, the lower outer circumferential surface of the outer cut part is formed in a curve, and the upper outer circumferential surface facing and in contact with the outer cut part is a tapered groove The upper part of the outer cut part and the inner cut part are located on the same line with respect to the X-axis, so that it is easy to cut during the finishing stage of the procedure and the external shape of the remaining part can be formed in a curve.

The cut portion is a spinal fixation device, characterized in that it satisfies the following condition (2).

<Condition 2>

C ₁ is the inclination angle (Degree) of the inner cut part with respect to the X axis, C ₂ is the upper inclination angle (Degree) of the outer cut part, and D ₁ means the radius of curvature (mm) of the lower part of the outer cut part.

The spine fixing screw includes a neck portion having an outer circumferential surface formed as a groove and positioned between the body portion and the head portion from the receiving member to be easily rotated at a predetermined angle, and the neck portion is positioned at one end of the groove. It may further include a rotation regulating unit in which the rotation angle is regulated so that the spinal fixation screw is not separated from the receiving member.

The spinal fixation screw may satisfy the following conditional expression (3).

<Condition 3>

S ₁ is an angle (Degree) of rotation based on the Y-axis of the spinal fixation screw, R ₂ is the radius of curvature of the groove of the neck part (mm), L ₂ is the length of the body part (mm), L ₃ is the head part and the length (mm) including the neck portion.

a rod positioned between the nut member and the head part and fixed at a predetermined interval between at least two vertebrae by connecting a plurality of the spine fixing screws; and a pressing relay member positioned between the head and the rod in the receiving member, the upper portion being pressed by the rod, and the lower portion pressing the head portion.

The nut member is tapered so that both corners of the lower end become narrower toward the center, and the center of the lower end is elastically deformed by pressing the end facing the rod or the head portion, or is elastically restored to its original shape when the pressure is released It may further include a restoration unit.

The nut member may further include an initial fastening part formed to be flat and inclined to facilitate initial fastening along the thread groove of the first fastening part at an end to which it is fastened among the outer peripheral surfaces of the lower end of the second fastening part.

In the spinal fixation device according to the present invention, the spinal fixation screw is prevented from being separated from the receiving member when the screw is rotated, and the receiving member is prevented from being bent even when the fastening strength is increased during fastening, thereby maintaining a continuous fixing force.

In addition, in the spinal fixation device according to the present invention, since the pressing relay member includes the first deformable part and the second deformable part, and the receiving member includes the receiving deformable part, pressure is evenly applied to the head of the spinal fixation screw by the pressing force of the rod. Therefore, it is possible to continuously maintain the fixing force of the spinal fixation screw.

In addition, in the spinal fixation device according to the present invention, one of the pressing relay member and the receiving member is further provided with a locking part, and the other has a locking groove further formed, thereby improving the fixing force so that the locking part is not separated from the locking groove. can

In addition, the spinal fixation device according to the present invention may further include a protective film on the incised neck to prevent fragments from being generated during cutting, and to prevent damage to internal tissues of the body due to the fractured surface of the incised neck.

1 is a cut-away cross-sectional view installed on the spine of a spinal fixation device according to an embodiment of the present invention.
Figure 2 is a cross-sectional view showing a spinal fixation device according to an embodiment of the present invention.
Figure 3 (a) is a side view of the receiving member of Figure 2 according to an embodiment of the present invention, Figure 3 (b) is a side view of the nut member.
4 is an enlarged cross-sectional view of portions 'A' and 'B' of the receiving member and the nut member of FIG. 2;
5 is an enlarged cross-sectional view of a main portion of a cut portion of a receiving member according to an embodiment of the present invention.
6 is an enlarged cross-sectional view of a cut portion showing another modified example of FIG. 5 .
7 is a perspective view illustrating a state in which a spinal fixation screw is rotated from a receiving member according to an embodiment of the present invention;
8 is a bottom view showing the body of the spinal fixation screw according to an embodiment of the present invention.
9 is a cross-sectional view showing a spinal fixation device according to another embodiment of the present invention.
10 is a perspective view and a cross-sectional view of the lower end of the nut member of FIG.
11 is a plan view (a) and a side view (b) of the pressing relay member of FIG.
Figure 12 (a) is a view for explaining the coupling relationship between the members of Figure 2, (b) is a view for explaining that the pressure relay member is deformed after installation.

Hereinafter, a spinal fixation device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. Here, the accompanying drawings are illustrated by exaggerating or simplifying a part for convenience and clarity of explanation and understanding of the configuration and operation of the technology, and each component does not exactly match the actual size.

As used herein, the term “Y-axis” may mean a central axis with respect to the direction of insertion into the spine 1 , and “X-axis” may mean a transverse direction orthogonal to the Y-axis. In addition, terms such as "first", "second", "one side", and "other side" used in the present invention are used to distinguish one component from another component, and each component is the term are not limited by

The vertebra 1 is a long bone structure supporting the body in the back part of the body, and in detail, it refers to the vertebrae composed of the cervical, thoracic and lumbar vertebrae. Accordingly, the vertebrae 1 referred to below may refer to at least one of them.

1 is a cross-sectional view of a spinal fixation device installed on the spine according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view showing the spinal fixation device according to an embodiment of the present invention.

1 and 2 , the spinal fixation device may include a spinal fixation screw 100 and a rod 500 for fixing the vertebrae 1 facing each other. The rod 500 may mutually fix another vertebra 1 positioned in the same row as any one vertebra 1 among the vertebrae 1 . The rod 500 is mainly made of elastic material and is formed in a cylindrical shape and can be connected after inserting the vertebral fixation screw 100 into the vertebrae of the upper and lower parts of the damaged disc. This connection can prevent the disc from being compressed by securing the distance between the vertebrae.

The spinal fixation screw 100 and the accommodating member 200 for accommodating the head portion 130 of the spinal fixation screw 100 may be included. The spine fixing screw 100 includes a body portion 150 having a screw thread formed therein, and a head portion 130 formed at one end of the body portion 150 . An insertion hole 153 may be formed in the body portion 150 . Through this insertion hole 153, a medical examination instrument such as an endoscope may be inserted or a filler such as bone cement (not shown) may be injected using an injector (not shown). In addition, when a plurality of holes are formed on the side of the body 150 of the spinal fixation screw 100, the bone cement may be injected more evenly. Accordingly, in the injection hole (not shown), bone cement (not shown) is radially evenly distributed and extruded, so that it can be firmly fixed to the vertebrae. In general, when the spinal fixation screw 100 is operated on the patient's spine 1 in an osteoporotic state, bone cement is injected into the patient's spinal cord 1 to obtain the necessary bone density, and the spinal fixation screw 100 and the spinal cord (1) can form osseointegration between.

1 and 2 , the spinal fixation device according to an embodiment may include a spinal fixation screw 100 , a receiving member 200 , a nut member 300 , a rod 500 and a pressure relay member 400 . can

The spinal fixation screw 100 fixes the vertebrae 1 facing each other, and includes a body 150 in which a vertebra fastening part 151, which is a screw thread to be inserted and fastened to the vertebrae 1, is formed, and the body part 150. It may be provided with a head portion 130 formed on one end of the.

The body 150 has an entire outer circumferential surface of a screw thread, and the bone diameter becomes thicker as the screw thread moves toward the head 130 , and the distal end inserted into the spine 1 may be tapered. The thread may be formed in a double-threaded structure. That is, in the double screw thread structure, the pitch between the threads is approximately 2.0 to 2.7 mm, and the lead of the screw thread may be formed in two turns. Accordingly, the body 150 has a double screw thread structure, and when inserted at the same depth, the number of rotations is lower than that of the single thread screw structure, so that it can be more easily inserted into the spine 1 . In addition, the body portion 150 cannot be easily separated unless a forceful instrument is used in the opposite direction to be inserted as the fixing force is increased with respect to the spine (1). The thread shape of the body 150 is formed to be easily inserted in the direction of insertion, and when separated in the opposite direction, it is not separable by general manpower and can be formed in various ways if it is a shape that allows it to be separated only by a specific removal device. can In addition, the insertion hole 153 may be formed in the entire inner center of the body 150 , and the injection hole 155 may be formed at the end of the body 150 by communicating with the insertion hole 153 . The present invention is not limited thereto, and at least one of the insertion hole 153 and the injection hole 155 may be formed in the body 150 , and neither may be formed.

The head part 130 is formed to be continuous with the body part 150 , and may serve to support the body part 150 from the receiving member 200 to be rotatable at a predetermined angle. In addition, the upper inner groove of the head unit 130 may have a hexa shape and may be formed by sanding after removing foreign substances, cutting oil, and completely drying moisture.

The accommodating member 200 includes a hollow body 210 having a first fastening part 230 formed therein, and a mounting part provided on one side of the body 210 to rotatably mount the head part 130 . (250) may be provided. The main body 210 may be provided with a channel hole 253 penetrating in the X-axis of the spinal fixation screw 100 , that is, transverse to the insertion direction. The channel hole 253 may be formed as a "U"-shaped groove so that the rod 500 fixed between the adjacent vertebrae 1 can be seated. In addition, the accommodating member 200 may be formed so that the main body 210 faces each other with the channel hole 253 interposed therebetween. The main body 210 may be separated and removed outside the body by being cut leaving the mounting part 250 in the treatment stage. Therefore, the spinal fixation device of an embodiment according to the present invention can install the spinal fixation screw 100 by using the receiving member 200 without a separate dedicated installation mechanism to install the spinal fixation screw 100 . In addition, when the receiving member 200 is inserted from the outside of the patient's skin to the inside, only a minimum skin area of about 2 cm can be incised, so that the patient recovers quickly after the procedure and side effects of the procedure can be reduced.

The nut member 300 is formed with a second fastening part 330 screw-coupled to the first fastening part 230 , and is positioned above the head part 130 and can be fixed. In addition, it may be installed so as to be lifted in the accommodating member 200 . The nut member 300 may be positioned on the rod 500 to apply pressure to the rod 500 in the insertion direction of the Y-axis of the spinal fixation screw 100 . When the inner circumferential surface of the accommodating member 200 is formed of a screw thread, the nut member 300 may be engaged and screwed together to further press the rod 500 to fix it.

The rod 500 is positioned between the nut member 300 and the head part 130, and by connecting a plurality of spinal fixing screws 100, it can be fixed at a predetermined interval between at least two vertebrae 1 .

The pressing relay member 400 is positioned between the head part 130 and the rod 500 in the receiving member 200 , and the upper part is pressed by the rod 500 , and the lower part is to be pressed by the head part 130 . can

Figure 3 (a) is a side view of the accommodating member according to an embodiment of the present invention, Figure 3 (b) is a side view of the nut member, Figure 4 is a portion 'A' and 'B' of the accommodating member and the nut member of FIG. is an enlarged cross-sectional view of

3 (a) and (b), D ₁ may mean the outer diameter (mm) of the inner diameter groove of the receiving member 200, D ₂ may mean the outer diameter (mm) of the nut member 300 . Preferably, D ₁ may be 9.5 to 10.5 mm, and D ₂ may have a difference in spacing between each other of 0.02 to 0.2 mm when 9.48 to 10.7 mm. Accordingly, the nut member 300 can be easily coupled to the receiving member 200, and wear due to friction can be somewhat reduced due to the tolerance.

Referring to 'A' of FIG. 4 , the first fastening part 230 may further include a first bending preventing part 231 and a grooved second bending preventing part 233 protruding in the insertion direction. The second bending prevention part 233 may have a groove formed at a position symmetrical to the left and right with respect to the first bending prevention part 231 and the Y axis. Therefore, the first bending prevention part 231 can prevent the receiving member 200 from being bent outward from the Y-axis by the pressure applied when the nut member 300 is inserted. In addition, the first fastening part 230 is located on the upper side of the screw thread and has a first inclined part 235 having an inclination angle, and the first inclined part 235 is located on the lower surface of the screw thread and has a smaller inclination angle than the first inclined part 235. It may be made of a second inclined portion 237 that is.

Referring to 'B' of FIG. 4 , the second fastening part 330 corresponds to the first bending preventing part 231 and has a first corresponding bending preventing part 331 and a first corresponding bending preventing part having a groove to be inserted during fastening. It may include a portion 331 and a second corresponding bending prevention portion 333 positioned to be left and right symmetrically with respect to the Y-axis. The second corresponding bending prevention part 333 may be inserted and protruded when fastening to correspond to the second bending prevention part 233 . In addition, the second fastening part 330 is located on the lower side of the screw thread and includes a first corresponding inclined part 335 inserted to correspond to the first inclined part 235, and a second inclined part 237 positioned on the upper surface of the screw thread. ) may be formed of a second corresponding inclined portion 337 inserted to correspond to.

Therefore, as the inclination angle of the first inclined portion 235 and the first corresponding inclined portion 335 is greater than that of the second inclined portion 237 and the second corresponding inclined portion 337, the initial fastening is easy and deformation is reduced. can be minimized.

Meanwhile, each of the first fastening part 230 and the second fastening part 330 may satisfy Equation 1 below.

Here, S ₁ is the inclination angle (Degree) of the first inclined part or the first corresponding inclined part inclined along the -x and -y axes with respect to the X axis, and S ₂ is the inclination of the second inclined part or the second corresponding inclined part. An angle (Degree), and P ₁ means a pitch between the first bending prevention part or the first corresponding bending prevention part, and L ₁ is the inner side surface of the first bending prevention part of the accommodating member or the nut member Means the length (mm) of the section of the outer side of the first corresponding bending prevention part. And D ₁ means the outer diameter (mm) of the receiving member inner diameter groove, D ₂ means the outer diameter (mm) of the nut member.

If the condition of Equation 1 (a) is out of the range, it is not easy to lower the nut member 300 from the receiving member 200 in the initial fastening or insertion direction during fastening, and the fastening time because the nut member 300 is inclined. There is a risk of this being delayed. In addition, when out of the condition range of (b) of Equation 1, the inclination angles of the first inclined portion 235 , the second inclined portion 237 , the first corresponding inclined portion 335 , and the second corresponding inclined portion 337 . It may have a square screw shape without teeth. Accordingly, the fastening time may be delayed or the fastening may not be easy. Even if it is fastened and fixed, the nut member 300 may be slightly loosened even by a small external vibration, and the function of the spinal fixation device may be lost. It may be difficult to easily fasten the nut member 300 with respect to 200, and when it exceeds the upper limit, the fastening area is reduced, and friction between the threads of the accommodating member 200 or the threads of the nut member 300 increases and there is a risk of damage have.

Accordingly, when the condition ranges of (a), (b) and (c) of Equation 1 are satisfied, the inclination angle (Degree) of the first inclined part 235 or the first corresponding inclined part 335 (S ₁ ) ) is approximately 5 ° to 15 °, the inclination angle (Degree) (S ₂ ) of the second inclined portion 237 or the second corresponding inclined portion 337 may be 20 ° to 60 °. In addition, the pitch (P ₁ ) between the first bending prevention part 231 or the first corresponding bending prevention part 331 is approximately 1.95-2.25mm, and the first bending prevention part 231 of the accommodating member 200 ) of the section length (L ₁ ) of the inner side or the outer side of the first corresponding bending prevention portion 331 of the nut member 300 may be approximately 0.65 ~ 0.75mm. And preferably D ₁ may be 9.5 ~ 10.5 mm, D ₂ may have a difference of 0.02 ~ 0.2 mm when the distance between each other when 9.48 ~ 10.7 mm. Accordingly, the nut member 300 can be easily coupled to the receiving member 200, and wear due to friction can be somewhat reduced due to the tolerance.

Accordingly, by satisfying Equation 1 (a), the initial fastening can be easily fastened at once, and the fastening time can be shortened as gravity is more applied to the insertion direction by the inclination angle. In addition, according to the satisfaction of Equation 1 (b), the first bending preventing unit 231 or the first corresponding bending preventing unit 331 is the pressure applied when the nut member 300 is inserted into the receiving member 200. Thus, it is possible to minimize or prevent deformation that is bent outward from the Y-axis.

5 is an enlarged cross-sectional view of a main part of a cut part according to an embodiment of the present invention.

Referring to FIG. 5 , the receiving member 200 may further include a cutout 270 having grooves formed on the outer and inner circumferential surfaces of the body 210 to be cutable along the X-axis with respect to the Y-axis.

The cut portion 270 may be formed of an outer cut portion 271 and an inner cut portion 273 with the main body 210 interposed therebetween based on the X-axis of the main body 210 being cut. The outer circumferential surface of the lower portion 271b of the outer cut portion 271 may be formed in a curved shape, and the outer circumferential surface of the upper portion 271a facing and in contact with the outer cut portion 271 may be formed as a tapered groove. In addition, the upper portion 271a of the outer cut portion 271 and the inner cut portion 273 may be located on the same line with respect to the X-axis.

On the other hand, as shown in FIG. 5 , it is not applied only to the groove shape of the outer cut portion 271 and the inner cut portion 273 , but can be applied in various shapes that are easy to cut but may have less tissue damage after removal.

Also, the cut portion 270 may satisfy Equation 2 below.

C ₁ is the inclination angle (Degree) of the inner cut part with respect to the X axis, C ₂ is the upper inclination angle (Degree) of the outer cut part, and D ₁ means the radius of curvature (mm) of the lower part of the outer cut part.

If (a) of Equation 2 is not satisfied, the thickness of the main body 210 between the outer cut portion 271 and the inner cut portion 273 becomes thinner, and there is a risk of breaking even before the receiving member 200 is cut. In addition, even if cut, a portion other than the desired cut portion 270 is cut, so there is a risk of tissue damage due to difficulty in the procedure and some residual cut portion 270 remaining. When (b) of Equation 2 is not satisfied, the distance between the upper surface of the outer cut portion 271a and the lower surface of the outer cut portion 271b may be narrowed, so that the cutting movable range of the upper surface 271b of the outer cut portion during cutting Because it is narrow, there is a difficulty in cutting with greater force and the cutting time may be delayed.

On the other hand, when (a) and (b) of Conditional Expression 2 are satisfied, the inclination angle (Degree) (C ₁ ) of the inner cut part is 90° with respect to the X axis, and the inclination angle (C ₂ ) of the upper part of the outer cut part is 135° and the radius of curvature (D ₁ ) of the lower surface 271b of the outer cut portion may be approximately 0.5 to 1 mm. Therefore, if conditional expression 2 (a) is satisfied, the thickness of the cut portion of the main body 210 is thicker when the receiving member 200 is cut, so the desired cut portion 270 is precisely cut by applying a small force using the principle of the lever. Since it can be cut easily, there is an advantage in that the operation time is shortened. In addition, when (b) of condition 2 is satisfied, cutting can be easy at the completion of the procedure, and as the outer shape of the lower surface 271b of the remaining part is curved, the cut surface is not sharp after the procedure. Because it does not cause damage, it has the effect of not causing an inflammatory reaction, which is a side effect. That is, the fracture surface of the cut portion 270 is formed as a curved surface to prevent damage to internal tissues of the body, and since it does not protrude like an accessory bone on the patient's skin after the procedure, physical activity can be freely performed in daily life.

6 is an enlarged cross-sectional view of a cut portion showing another modified example of FIG. 5 .

Referring to FIG. 6 , the spinal fixation device according to another embodiment of the present invention may further include a receiving member 200 having a protective film 290 on the surface of the cut portion 270 . A protective film 290 may be formed on at least one of the inner cut portion 273 and the outer cut portion 271 of the cut portion 270 . In addition, a portion of the protective film 290 may remain on the accommodating member 200 remaining while the accommodating member 200 is removed by the cutting part 270 . Accordingly, the protective film 290 may prevent fragments from being generated during cutting, and may prevent damage to internal tissues of the body due to the fracture surface of the cut portion 270 . The protective film 290 may be formed on the inner and outer circumferential surfaces of the cut portion 270 and made of silicon, a material harmless to the human body that serves as a lubricant.

7 is a perspective view illustrating a state in which the spinal fixation screw is rotated from the receiving member according to an embodiment of the present invention.

Referring to FIG. 7 , the spinal fixation screw 100 according to an embodiment of the present invention has an outer circumferential surface formed of a groove and is positioned between the body portion 150 and the head portion 130 from the receiving member 200 at a predetermined angle. A neck portion 170 made to be easily rotated may be included.

The neck unit 170 may include a rotation regulating unit 175 positioned at one end of the groove. The rotation regulating unit 175 may regulate the rotation angle so that the spinal fixation screw is not separated from the receiving member 200 .

In addition, the spinal fixation screw 100 may satisfy Equation 3 below.

S ₁ is an angle (Degree) of rotation based on the Y-axis of the spinal fixation screw, R ₂ is the radius of curvature of the groove of the neck part (mm), L ₂ is the length of the body part (mm), L ₃ is the head part and the length (mm) including the neck portion.

If, when the condition (a) of Equation 3 is deviated, there is a risk of separation from the accommodating member 200 . In addition, since the rotation angle of the condition (a) of Equation 3 does not come out when it deviates from the condition (b) of Equation 3, the rotation of the accommodation member 200 including the rod 500 after being fixed to the spine 1 This can be difficult. In addition, when the condition (c) of Equation 3 is deviated, it may be difficult to fix the spinal fixation screw 100 for a long time after being implanted in the spine 1 .

Therefore, if the condition of Equation 3 is satisfied, the spinal fixation screw 100 can be implanted and fixed in the spine 1 for a long time, and after being fixed, the rotation angle of the receiving member 200 including the rod 500 is Y It can be rotated from 0 to 30° about its axis.

8 is a bottom view showing the body of the spinal fixation screw according to an embodiment of the present invention.

Referring to FIG. 8 , the body 150 may further have a pressure reducing groove 157 formed on at least one side thereof. When the vertebra fastening part 151 formed with a screw thread is inserted into the spine 1, the internal contact area expands and the implantation torque and pressure increase, so that tissue cells may be destroyed. At this time, if the implantation torque is too high, necrosis of the tissue cells of the spine (1) occurs, and there is a high probability of failure in important osseointegration after spinal surgery. In particular, the higher the resistance area and shear force in the contact portion of the spine 1, and the harder the bone, the higher the implantation torque.

Meanwhile, the pressure reducing groove 157 may satisfy Equation 4 below.

Here, R ₃ means an angle inclined with respect to the horizontal direction.

When the lower limit and upper limit of the condition range of Equation 4 are out of the range, the function of reducing pressure may be reduced because there is a risk of damaging the bone tissue during fastening from the bone surface. Accordingly, when the condition range of Equation 4 is satisfied, as the pressure reducing groove 157 is formed on one side of the lower end of the body 150, the resistance area, shear force, implantation torque and pressure of the spine 1 can be reduced. That is, since the pressure reduction groove 157 can minimize the pressure increase due to the insertion into the spine 1, it is possible to minimize damage to the bone tissue. In particular, when the pressure reducing groove 157 further includes at least one pressure reducing groove 157 at a position symmetrical left and right and up and down, and R ₃ satisfies 76.3°, even if it is implanted in the spine 1 for a long period of time, it does not cause inflammation. It adheres well and does not cause side effects.

9 is a cross-sectional view showing a nut member according to another embodiment of the present invention.

Referring to FIG. 9 , the nut member 900 according to another embodiment of the present invention may further form an elastic restoration part 910 . The elastic restoration part 910 may be tapered so that it becomes narrower toward the center of the hole from the thread ending at the bottom end. The height of the tapered section may be approximately 0.1 to 0.5 mm. If it is less than 0.1 mm, the role of elastic restoration may be insufficient, and if it exceeds 0.5 mm, there is a risk that the accommodating member 200 may be opened due to too large tolerance when the nut member 900 is fastened from the accommodating member 200. . Therefore, when the height at which the elastic restoration part 910 is formed with respect to the nut member 900 is approximately 0.1 to 0.5 mm, the center of the lower end presses the end facing the rod 500 or the head part 130 to elastically deform it. Or it can be restored to its original shape when the pressure is released. That is, when the position of the spine fixing screw 100 fixed to the spine 1 is changed during the initial operation, the coupling of the nut member 900 from the receiving member 200 may be released. At this time, the lower end of the nut member 900 may be restored to the initially fastened form without being deformed.

10 is a perspective view and a cross-sectional view of a lower end of the nut member of FIG.

Referring to FIG. 10 , the nut member 300 may further include an initial fastening part 370 at the end to which it is fastened among the outer peripheral surfaces of the lower end of the second fastening part 330 . The initial fastening part 370 slides when in contact with the first fastening part 230 as it is formed flat and inclined for easy initial fastening along the threaded groove of the first fastening part 230 to quickly find and fasten the threaded groove position. can

11 is a plan view (a) and a side view (b) of the pressing relay member of FIG. 2 .

Referring to Figure 11 (a), any one of the pressing relay member 400 and the receiving member 200 is further provided with a locking portion 450, the other one may be further formed with a locking groove 261. . Accordingly, the spine fixing screw 100 may prevent the locking portion 450 from being separated from the locking groove 261 .

Referring to (b) of FIG. 11 , inside the pressure relay member 400 , the second relay deformable part 430 may be formed so that both sides thereof are symmetrical. The second relay deformable portion 430 may further form a spare groove portion 470 therebetween. The spare groove portion 470 is the second relay deformable portion 430 is deformed when the pressing relay member 400 is pressed by the rod 500 to serve as an extra space to further fix the head portion 130. can That is, the spare groove portion 470 may have an interval of up to 3 mm in normal times, but the space between the rods 500 may be narrowed when the pressure is applied. On the other hand, the present invention is not limited thereto, and the second intermediate deformable portion 430 may be formed as a semicircular groove having the same center as the spare groove portion 470 .

Figure 12 (a) is a view for explaining the coupling relationship between the members of Figure 2, (b) is a view for explaining that the pressure relay member is deformed after installation.

12 (a) and 12 (b), the mounting portion 250 may further include a receiving deformable portion (260). The accommodating deformable part 260 has a head part 130 installed, and when the rod 500 is pressed, it can be deformed while in close contact with the entire lower end of the head part 130 .

The pressure relay member 400 is made of an elastic material, and may be positioned between the head 130 and the rod 500 in the accommodating member 200 . The pressing relay member 400 may have an upper surface pressed by the rod 500 and a lower surface pressing the head unit 130 . In addition, the pressurizing relay member 400 may include a first relay deforming part 410 formed in the center of the upper surface and a second relay deforming part 430 formed in the lower surface.

Referring to FIG. 12 ( a ), when the rod 500 initially descends and presses the spinal fixation screw 100 , the lower portion of the rod 500 is the first relay deformable part 410 of the pressing relay member 400 . It is in contact with both end points in contact with and both ends of the pressure relay member 400 may also descend in the direction of the head unit 130 . In addition, the second relay deformable portion 430 of the pressure relay member 400 may come into contact with the upper end point of the head portion 130 , and the lower end of the head portion 130 has a locking groove 261 of the receiving member 200 . ) can be tangent to one side of the This point contact can increase the temporary fixing force of the spinal fixation screw 100 . However, in order to increase the long-term fixation force, the surface contact can increase the fixation force more than the point contact.

Referring to FIG. 12 ( b ), the first relay deformable part 410 is in close contact with the entire lower end of the rod 500 when the rod 500 is pressed, and the outer peripheral surface of the pressing relay member 400 is the head part 130 . direction can be deformed. That is, the first relay deformable part 410 has a radius of curvature R ₄ that is less than or equal to the radius R _a of the rod 500 , so that the nut member 300 is lowered by the pressure applied to the rod 500 . Due to this, the rod 500 may press the first relay deformable part 410 while being in surface contact. At this time, at least one expansion groove (not shown) may be further formed so that the first relay deformable part 410 can be more closely attached to the entire lower end of the rod 500 . The expansion groove (not shown) installs a large rod 500 or further expands the first relay deformable part 410 due to an increase in the load of the rod 500 pressure over time, resulting in loss and It can play a role in reducing damage. The expansion groove (not shown) may have various shapes, such as a spherical surface, a triangular surface, and a square surface.

In addition, the second relay deformable portion 430 may be installed in close contact with the entire upper portion of the upper end of the head portion 130 when the outer circumferential surface is deformed as the lower end of the pressure relay member 400 . The radius of curvature (R ₅ ) of the second relay deformable part ( 430 ) may be smaller than or equal to the radius (R _b ) of the upper part of the head part ( 130 ). Accordingly, due to the pressure applied to the rod 500 while the nut member 300 is descending, the second relay deformable part 430 may be installed so as to closely and wrap the entire upper end of the head part 130 . In this case, the head 130 may reduce the pressure load applied from the rod 500 by the second relay deforming part 430 , but may have the same center or a maximum spacing of 3 mm.

Therefore, the radius of curvature (R ₄ ) of the first relay deforming part 410 is less than or equal to the radius (R _a ) of the rod, and the radius of curvature (R ₅ ) of the second relay deforming part 430 is the head part 130 . ) is smaller than or equal to the upper radius (R _b ), and the radius of curvature (R ₆ ) of the receiving deformation part 260 may be greater than or equal to the lower radius (R _c ) of the head unit 130 . That is, the first relay deformation unit 410 , the second relay deformation unit 430 , and the accommodation deformation unit 260 may satisfy all of (a) to (c) of Equation 5 below.

Here, R ₄ means the radius of curvature of the first intermediate deformation portion, R ₅ means the radius of curvature of the second intermediate deformation portion, and R ₆ means the radius of curvature of the receiving deformation portion. R _a means the radius of the rod, R _b means the upper radius of curvature of the head part, and R _c means the lower radius of curvature of the head part.

That is, when R ₄ in Equation 5 (a) is greater than R _a , a free space is created in the first relay deforming part 410 , so the function of holding the rod 500 is lowered, and the rod 500 is located on the spine. It may be separated from the set screw 100 . When R ₅ in Equation 5 (b) is greater than R _b , the second relay deforming part 430 can accommodate the entire upper part of the head part 130, but gradually increases by the force of the accommodating member 200 being pressed to the side. Since a space is created in the upper part of the head 130 and pushes the rod 500, the fixing force may be reduced. When R ₆ of Equation 5 (c) is smaller than R _c , the accommodating deformable part 260 cannot accommodate the lower part of the head 130, so that the spinal fixation screw 100 may be separated from the accommodating member 200. have.

Accordingly, when all of the condition ranges of Equations 5 (a) to (c) are satisfied, the first relay deforming unit 410 may surface-contact the lower portion of the rod 500 to increase adhesion and fixing force. In addition, the second relay deformable portion 430 and the receiving deformable portion 260 each make surface contact with the upper and lower portions of the head 130, so that the head 130 can be stably supported from the receiving member 200, Even when the body portion 15 rotates, it can have continuous adhesion and fixing force. Specifically, R ₄ is 2.5 to 2.75 mm, R ₅ is 2.55 mm, R ₆ is 4.1 mm, Ra is 2.75 to 3.mm, R _b is _{3 to 3.9 mm, and R c is} 3.9 to 4.1 mm. A point when the upper curvature of the first relay deforming part 410 and the rod 500, the second intermediate deforming part 430 and the head 130, and the lower curvature of the receiving deformable part 260 and the head 130 respectively contact each other. Stable and continuous bonding force and fixation force can be increased by surface contact rather than contact.

Referring to FIG. 12( b ), as the nut member 300 is more strongly fastened than in FIG. 12( a ), the pressing force may be increased by the descending force of the rod 500 . At this time, the lower portion of the rod 500 can be in contact with the overall surface as the first relay deforming part 410 is deformed, and at the same time, both ends of the pressure relay member 400 are descended in the direction of the head part 130 as well as the pressure relay member. The second relay deformable part 430 of 400 may be in contact with the entire upper surface of the head part 130 . In addition, the side and lower ends of the head portion 130 may be in contact with the overall surface of the accommodation deformable portion 260 of the accommodation member 200 . Accordingly, the pressing relay member 400 has the first relay deformable part 410 and the second relay deformable part 430 , and the receiving member 200 has the receiving deformable part 260 , so that the rod 500 and the spine By relaying the pressure between the fixing screws 100 , it is possible to evenly distribute the pressure and maintain a continuous fixing force.

The above-described embodiments are merely exemplary, and various modifications and equivalent other embodiments are possible by those of ordinary skill in the art to which the present invention pertains. Therefore, the true technical protection scope of the present invention will have to be determined by the technical idea of the invention described in the claims.

1: vertebra 5: spinal cord
100: spine fixing screw 130: head portion
150: body part 151: spine fastening part
153: insertion hole 155: injection hole
157: pressure reducing groove 170: neck portion
175: rotation control unit 200: receiving member
210: body 230: first fastening part
231: first bending prevention part 233: second bending prevention part
235: first inclined portion 237: second inclined portion
250: mounting portion 253: fastening hole
260: accommodating deformation part 261: locking groove
270: cut 271: outer cut
271a: upper surface of the outer cut part 271b: the lower surface of the outer cut part
273: inner cut 290: protective film
300, 900: nut member 330: second fastening part
331: first corresponding bending prevention part 333: second corresponding bending prevention part
335: a first corresponding inclined unit 337: a second corresponding inclined unit
370: initial fastening portion 400: pressure relay member
410: first relay deformation part 430: second relay deformation part
450: locking part 470: spare groove part
500: rod 910: elastic restoration part

Claims (11)

In the spine fixing device for fixing the vertebrae facing each other,
a spinal fixation screw having a body in which a vertebral fastening part which is a screw thread to be inserted and fastened to the vertebra is formed, and a head part formed at one end of the body;
A hollow body having a first fastening portion formed therein, and a mounting portion provided on one side of the main body to rotatably mount the head, the main body penetrates through the X-axis with respect to the Y-axis of the spinal fixation screw a receiving member in which a channel hole is formed; and
A hollow side surface is formed with a second fastening part screw-coupled to the first fastening part, and a nut member positioned above the head part for fixing;
The first fastening part,
a first bending prevention part protruding in the insertion direction to prevent the accommodating member from being bent by the pressure applied when the nut member is inserted; and
A groove is formed at a position symmetrical to the left and right with respect to the first bending prevention part and the axis, and a second bending prevention part is formed to prevent the accommodating member from bending,
The second fastening part,
a first corresponding bending preventing part having a groove formed therein to correspond to the first bending preventing part and being inserted during fastening; and
Spinal fixation device, characterized in that it is positioned symmetrically to the left and right with respect to the first corresponding bending prevention part and the axis, and comprising a second corresponding bending prevention part protrudingly formed to correspond to the second bending prevention part and inserted when fastening. According to claim 1,
The first fastening part,
It consists of a first inclined part positioned on the upper side of the screw thread and having an inclination angle, and a second inclined part positioned adjacent to the lower surface of the screw thread to have an inclination angle smaller than that of the first inclined part,
The second fastening part,
It consists of a first corresponding inclined part positioned on the lower surface of the screw thread and inserted corresponding to the first inclined part, and a second corresponding inclined part positioned on the upper surface of the screw thread and inserted corresponding to the second inclined part,
The spinal fixation device, characterized in that the initial fastening is easy and deformation is minimized as the inclination angle of the first inclined portion and the first corresponding inclined portion is greater than that of the second inclined portion and the second corresponding inclined portion. 3. The method of claim 2,
Each of the first fastening part and the second fastening part satisfies the following conditional expression (1).
<Condition 1>

Here, S ₁ is the inclination angle (Degree) of the first inclined part or the first corresponding inclined part inclined along the -x and -y axes with respect to the X axis, and S ₂ is the inclination of the second inclined part or the second corresponding inclined part. An angle (Degree), and P ₁ means a pitch between the first bending prevention part or the first corresponding bending prevention part, and L ₁ is the inner side surface of the first bending prevention part of the accommodating member or the nut member Means the length (mm) of the section of the outer side of the first corresponding bending prevention part. And D ₁ means the outer diameter (mm) of the receiving member inner diameter groove, D ₂ means the outer diameter (mm) of the nut member. According to claim 1,
The receiving member is
Spinal fixation device, characterized in that it further comprises a cutout portion formed on the outer peripheral surface and the inner peripheral surface of the main body to be cut in the X-axis with respect to the Y-axis. 5. The method of claim 4,
The cut part,
It consists of an outer cut part and an inner cut part between the main body based on the X-axis to be cut of the main body,
The lower outer circumferential surface of the outer cut portion is formed in a curved shape, and the upper outer circumferential surface facing and in contact with the outer cut portion is formed as a tapered groove, and the upper portion of the outer cut portion and the inner cut portion are located on the same line with respect to the X axis to finish the procedure Spinal fixation device, characterized in that it is easy to cut during the step and the external shape of the remaining part is formed in a curved shape. 6. The method of claim 5,
The cut portion is a spinal fixation device, characterized in that it satisfies the following condition (2).
<Condition 2>

C ₁ is the inclination angle (Degree) of the inner cut part with respect to the X axis, C ₂ is the upper inclination angle (Degree) of the outer cut part, and D ₁ means the radius of curvature (mm) of the lower part of the outer cut part. 7. The method according to any one of claims 1 to 6,
The spinal fixation screw,
The outer peripheral surface is formed with a groove and is positioned between the body portion and the head portion from the receiving member and includes a neck portion configured to be easily rotated at a predetermined angle,
The neck portion,
Spinal fixation device, which is located at one end of the groove, further comprising a rotation regulating unit for regulating the rotation angle so that the spinal fixation screw is not separated from the receiving member. 8. The method of claim 7,
The spinal fixation device, characterized in that the spinal fixation screw satisfies the following condition (3).
<Condition 3>

S ₁ is an angle (Degree) of rotation based on the Y-axis of the spinal fixation screw, R ₂ is the radius of curvature of the groove of the neck part (mm), L ₂ is the length of the body part (mm), L ₃ is the head part and the length (mm) including the neck portion. 7. The method according to any one of claims 1 to 6,
a rod positioned between the nut member and the head part and fixed at a predetermined interval between at least two vertebrae by connecting a plurality of the spine fixing screws; and
Spinal fixation device, characterized in that it is positioned between the rod and the head in the receiving member, the upper portion is pressed by the rod, the lower portion further comprises a pressurizing relay member for pressing the head portion. 7. The method according to any one of claims 1 to 6,
The nut member,
Both edges of the lower end are tapered so as to become narrower toward the center, and the center of the lower end is elastically deformed by pressing the end facing the rod or the head portion, or an elastic restoring unit that is restored to its original shape when the pressure is released. Spinal fixation device, characterized in that. 7. The method according to any one of claims 1 to 6,
The nut member,
The spinal fixation device, characterized in that it further comprises an initial fastening part formed flat and inclined to facilitate initial fastening along the thread groove of the first fastening part at an end of the outer peripheral surface of the lower end of the second fastening part to be fastened.

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