KR20210154533A - Artificial disc - Google Patents

Abstract

Disclosed is an artificial disc which is installed between a first vertebra and a second vertebra positioned at lower and upper parts, respectively. The disclosed artificial disc comprises: a first plate which is installed on the upper part of the first vertebra, has at least one first fixing protrusion formed on one surface in contact with the first vertebra to prevent separation, and has a first receiving groove formed on the other surface; a second plate which is installed on the lower part of the second vertebra so as to be spaced apart to face the first plate, has at least one second fixing protrusion formed on one surface in contact with the second vertebra to prevent separation, and has a second receiving groove formed on the other surface; and a core moving member which is positioned between the first receiving groove and the second receiving groove, reduces shock and noise while performing a relatively translational motion with respect to the first plate, and relatively rotates with respect to the second plate, wherein each of the first plate and the second plate has a length difference (Lg) drawn into the front (A) between a length (L1) to the rear end of the first plate and a length (L2) to the rear end of the second plate from the center line (CL), and does not interfere with the nerve roots even if the first vertebra and the second vertebra move to the back (B).

Description

artificial disc {ARTIFICIAL DISC}

The present invention relates to an artificial disk, and more particularly, to an artificial disk that can be implanted for a long time without causing pain and minimizing nerve compression even when the distance between vertebrae is narrowed during daily activities of a patient.

The spine is a long bone structure that supports the body at the back of the body. consist of. A disc (intervertebral disc), a strong connective tissue connecting neighboring vertebrae, is interposed between the remaining vertebrae except for the sacrum and tailbone. At this time, the disc can act as a cushion between the vertebrae, that is, a shock absorption function during weight-bearing. It also allows movement between the upper and lower vertebrae.

On the other hand, due to aging such as degenerative changes, physical overload, strong external shock, incorrect posture, etc., the nucleus pulposus in the disc penetrates the annulus fibrosus, the outer layer, and compresses the surrounding nerves, causing pain. If the function of such a disk is lost, it can be replaced with an artificial disk having the same function. This artificial disc can restore and maintain the original disc's height, which has been lowered by the sap of the existing disc, as well as restore the disc's ability to move naturally. Accordingly, various types of spinal artificial discs are currently being developed and used.

However, in the conventional artificial disc for the spine, the upper plate of the artificial disc compresses the nerve roots, causing pain as the distance between the posterior vertebrae is narrowed during daily activities such as stretching or sleeping, in which the patient tilts the body backward after implantation. There is a problem with making Therefore, there is a limitation in that patients who have been operated in daily life complain of discomfort or have to undergo re-implantation surgery.

Registered Patent Publication No. 10-1484073 (2015.01.22.) Registered Patent Publication No. 10-1964862 (2019.03.27.) US Patent Publication No. 2016-0317319 (2016.11.03.) US Registered Patent Publication No. 9,655,739 (2017.05.23.)

The present invention was devised in view of the above points, and an object of the present invention is to provide an artificial disc that does not interfere with nerve roots and thus does not cause pain.

In order to achieve the above object, the present invention is an artificial disc installed between the first vertebrae and the second vertebra respectively positioned in the lower part and the upper part, to be installed in the upper part of the first vertebrae, the first vertebra and a first plate having at least one first fixing protrusion formed on a contacting surface to prevent separation and having a first receiving groove formed on the other surface thereof; It is installed on the lower part of the second vertebrae so as to face the first plate and spaced apart from the first plate, and has at least one second fixing protrusion formed on one surface in contact with the second vertebra to prevent separation, and on the other surface a second plate on which a second receiving groove is formed; and a core moving member positioned between the first receiving groove and the second receiving groove, reducing shock and noise while performing a relative translational motion with respect to the first plate, and rotating relatively with respect to the second plate. Including, wherein each of the first plate and the second plate is a front between the length (L _{1 ) from the center line (CL) to the rear end of the first plate and the length (L 2} ) from the rear end of the second plate Even if the first and second vertebrae move posteriorly (B) with the length difference (L _g ) introduced in (A), it can be made so as not to interfere with the nerve roots.

The core moving member is installed in contact with the second accommodating groove, the rotational movement portion is formed in a curved surface to rotate relative to the second plate; A plan that is located on the lower surface of the core moving member, is installed in contact with the first accommodating groove, and prevents separation within the first accommodating groove and reduces shock and noise while performing a relative translational motion with respect to the first plate chapter; and a neck part interposed between the rotational motion part and the flange part, which locks in the first accommodating groove so that the flange part can be installed to be matched, and reduces shock and noise during the translational motion of the core moving member.

The core motion member is installed between a portion of the core motion member and the first plate, and a third accommodating groove is formed therein. It may further include a buffer member for alleviating noise.

The core movement member is installed in contact with the buffer member and a translational movement unit for relatively translational movement with respect to the first plate together with the buffer member; a rotational movement part connected to the translational movement part and installed in the second receiving groove, the rotational movement part being formed in a curved surface so that the second plate rotates relative to the core movement member; and a neck portion interposed between the translational movement part and the rotational movement part, and locking the side surface of the first receiving groove while the translational movement part supports the load of the rotational movement part.

The first plate and the second plate may satisfy Conditional Expression 1 below.

<Condition 1>

Here, L ₁ is the length from the center line CL of the first plate 110 to the rear end of the first plate 110, and L _g is the rear of the second plate 170 from the center line CL. It means the difference in length leading to the front (A) between the length to the end (L ₂ ) and L _{1 .}

It may further include at least one elastic member formed as a band to surround the first plate and the second plate to prevent separation from each other, limit the movement of the core movement unit and restore to the initial position.

At least one of the flange portion and the cushioning member of the core moving member positioned in the transverse length of the first plate or facing the transverse length of the edge of the first accommodating groove in each of the first plate and the core moving member It may further include a movable limiting part, characterized in that a protrusion or groove is formed so as to limit or block the translational and rotational movement of the core moving member in the transverse length from the first plate as being located in any one.

The artificial disc according to the present invention has a range of maximum internal angle between the first plate and the second plate when the first plate and the second plate come close to each other. there is no

_{The artificial disc according to the present invention has a length (L 1} ) from the center line (CL) of the first plate to the rear end of the first plate in the front (A) of the patient's body at a predetermined interval (L _g ). By having the second plate, there is an effect of not causing pain by minimizing the pressure on the nerve roots around the spine even when the patient moves.

1 is a cross-sectional view showing a state in which an artificial disk according to an embodiment of the present invention is installed after being inserted in A and B directions between adjacent cervical vertebrae.
Figure 2 is a side cross-sectional view showing a state in which the artificial disk according to an embodiment of the present invention is installed between the vertebrae and operated when the vertebrae are tilted in the B direction.
Figure 3a is a plan view showing a conventional artificial disk installed between the vertebrae, Figure 3b is a plan view showing the artificial disk according to an embodiment of the present invention.
Figure 4 is an exploded view showing an artificial disc according to an embodiment of the present invention.
5 is an exploded cross-sectional view taken along the line V-V' of FIG. 4;
6 is an exploded view showing an artificial disc according to another embodiment of the present invention.
7 is an exploded cross-sectional view taken along line VII-VII' of FIG. 6;
Figure 8a is an assembly cross-sectional view showing a first embodiment of the artificial disk according to another embodiment of the present invention.
Figure 8b is an assembly cross-sectional view showing a second embodiment of the artificial disc according to another embodiment of the present invention.
Figure 9 is a front view showing the second plate of the artificial disk according to another embodiment of the present invention.
10 is a cross-sectional view showing a core moving member according to a first modified example of an artificial disk according to another embodiment of the present invention.
11A is a cross-sectional view showing a core moving member according to a second modified example of an artificial disk according to another embodiment of the present invention.
11B is a plan view illustrating the rotational movement unit of FIG. 11A;
12A is a cross-sectional view showing a core moving member according to a third modified example of an artificial disk according to another embodiment of the present invention.
Figure 12b is a plan view showing the rotational movement unit of Figure 12a.
13 is a cross-sectional view showing an enlarged main part of an artificial disk according to an embodiment or another embodiment of the present invention.
Figure 14 is a cross-sectional view showing the C, D direction operating state of the artificial disk according to an embodiment or another embodiment of the present invention.
Figure 15a is a plan view showing that the artificial disk further includes an elastic band according to an embodiment or another embodiment of the present invention, Figure 15b is a side cross-sectional view of Figure 15a from the side.
16 is a plan view (a) and a side cross-sectional view (b) of an artificial disc according to another embodiment of the present invention.

Hereinafter, an artificial disc 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.

First, a direction will be defined for the description of the present invention. When the artificial disc is inserted into the patient's spine, the direction toward the front (front) of the treated patient is referred to as 'A' (front) for convenience of explanation, and the opposite direction, that is, the direction toward the back (rear) of the treated patient is referred to as 'B' (rear) for convenience of explanation. In addition, for convenience of explanation, 'left and right' means directions located on the left and right while being perpendicular to the two-dimensional translational image on the line connecting A and B. For convenience of explanation, 'C' (left) and 'D' (right) It is said In addition, the vertical length of the artificial disk located between the 'A' and 'B' directions is referred to as 'vertical length' for convenience, and the horizontal length of the artificial disk located between the 'C' and 'D' directions is referred to as 'horizontal length'. It is said

1 is a cross-sectional view showing a state in which an artificial disk 100 according to an embodiment of the present invention is installed after being inserted in the direction A to B between the second vertebrae 3 and the first vertebrae 1 of the vertebrae. Here, the spine is a long bone structure supporting the body at the back of the body, and in detail, refers to the vertebrae composed of the cervical, thoracic, and lumbar vertebrae. Accordingly, the spine referred to in the drawings may refer to at least one of them.

The first vertebra 1 means a vertebra (lower vertebrae) located in the lower part, and the second vertebra 3 means a vertebrae (upper vertebrae) located in the upper part corresponding to the first vertebra 1 . The artificial disc 100 according to an embodiment of the present invention is installed between the first vertebrae 1 and the second vertebrae 3, and when a doctor or operator installs it, the A-direction (front), that is, the front of the patient to be operated ( It can be installed in the B direction (rear) in the direction facing the front), that is, in the direction facing the rear (rear) of the patient to be treated. In addition, the first vertebrae 1 and the second vertebrae 3 have the smallest size among the vertebrae and are formed in a 'C' shape as a whole. do For example, in 'head nodding', the first and second vertebrae (1) (3) can move in A and B directions, and in 'head shaking and rotation', A, B, C and D The first vertebrae and the second vertebrae (1) (3) may move in at least one of the directions.

Referring to FIG. 1 , the artificial disk 100 according to an embodiment of the present invention may include a first plate 110 , a second plate 170 , and a core movement member 250 .

The first plate 110 is formed on one surface of the vertebrae in contact with the first vertebra 1 and has at least one first fixing protrusion 115 for preventing separation, and a first receiving groove 111 on the other surface thereof. can be formed.

The second plate 170 is spaced apart from the first plate 110 to face it, and is installed under the second vertebra 3 among the vertebrae and is formed on one surface in contact with the second vertebra 3 to prevent separation. and at least one second fixing protrusion 175, and a second accommodating groove 171 may be formed on the other surface thereof.

The core movement member 250 is positioned between the first accommodating groove 111 and the second accommodating groove 171 , and reduces shock and noise while moving relatively parallel to the first plate 110 , and the second It may rotate relative to the plate 170 .

In addition, each of the first plate 110 and the second plate 170 may satisfy Equation 1 below.

Here, L ₁ is the length from the center line CL of the first plate 110 to the rear end of the first plate 110, and L _g is the rear of the second plate 170 from the center line CL. It means the difference in length leading to the front (A) between the length to the end (L ₂ ) and L _{1 .}

If it is out of the lower limit of Conditional Expression 1, it may interfere with the nerve roots passing between the first and second vertebrae (1) and (3) when inclined in the B direction, and even a small movement of the second plate 170 causes the nerve root (5) ) may be under pressure. In addition, when the upper limit of Conditional Expression 1 is exceeded, the second plate 170 exposes the core exercise member 250 and there is a risk that the core exercise member 250 may be dislodged upward, and when the vertebrae are inclined in the B direction, nerves Compression can cause pain. In particular, when the length of Lg exceeds 2 mm, the second plate 170 is very close to the part of the core moving member 250, and thus separation may occur. In addition, since the load from the second plate 170 is not evenly received, the load is concentrated in the direction of Lg, so that non-uniform deformation of the core moving member 250 may occur.

Therefore, if conditional expression 1 is satisfied, it is possible to prevent the core exercise member 250 from being separated and to not cause pain because it does not interfere with the nerve roots 5 around the vertebrae even when the vertebrae are inclined in the B direction. In detail, _{the length of L 1} may be 6.5 mm to 8.5 mm, and when the length of Lg is 0.5 mm to 2 mm, it is most suitable for use as an artificial disc including thoracic, lumbar and cervical vertebrae.

Figure 2 is a side cross-sectional view showing an operating state when the artificial disc is installed between the vertebrae according to an embodiment of the present invention when the vertebrae are tilted in the B direction.

Referring to FIG. 2 , in the artificial disk 100 according to an embodiment of the present invention, the second plate 170 moves in the A direction with respect to the first plate 110 to indicate an internal angle therebetween. In this case, the range of the inner maximum angle θ in the B direction may be 20° to 25°. On the other hand, the artificial disk 100 according to an embodiment of the present invention when the second plate 170 is in contact with the first plate 110 in the A direction, that is, when the operation patient is prone to motion. The buffer member 357 located in the first receiving groove 111 can move in the opposite direction B in parallel. The translational movement of the buffer member 357 may have the effect of preventing the core movement unit 350 from being separated from the first plate 110 , alleviating the impact, and reducing noise.

In addition, in the artificial disk 100 , the second plate 170 moves in the B direction with respect to the first plate 110 to indicate an internal angle therebetween. At this time, the range of the inner maximum angle θ in the A direction may be 20 to 25˚. On the other hand, in the artificial disk 100 according to an embodiment of the present invention, when the second plate 170 approaches each other in the B direction with respect to the first plate 110 , that is, the operation in which the patient bends backward (rearward) When performing, the buffer member 357 located in the first accommodating groove 111 may perform a translational movement in the opposite direction A. The translational movement of the cushioning member 357 may have the effect of preventing the separation of the core moving part 350 from the second plate 170, alleviating the impact, and reducing the noise.

Figure 3a is a plan view showing a conventional artificial disk installed between the vertebrae, Figure 3b is a plan view showing the artificial disk according to an embodiment of the present invention.

Referring to Figure 3a, the intervertebral disc structure is a nerve root ( nerve root) (5) is located. Although the disk having the original nucleus pulposus should be located in the vertebral plane, a conventional artificial disk (D) to replace it may be located. However, the conventional artificial disc (D) when the first vertebra (1) is tilted backward (B) interferes with the upper plate pressing the nerve root (5) passing between the first vertebra (1) and the vertebral arch (7). This has the disadvantage of causing pain to the patient.

As shown in Fig. 3b, the artificial disc 100 according to the present invention is inserted and installed from the front (A) to the rear (B) between the first vertebrae (1) and the second vertebrae (3), and the rear (B) side The length of the second plate 170 is shorter than the length of the first plate 110 and does not interfere with the nerve root 5 passing between the first vertebrae 1 and the vertebral arch 7 . Accordingly, there is an effect of reducing discomfort when the patient tilts in the B direction during sleep or light exercise during daily life. On the other hand, the square corners of the first plate 110 and the second plate 170 of the artificial disk 100 according to the present invention may be formed to be rounded in a curve. Due to this shape, it is possible to minimize the compression of the nerve root 5 during translation and rotation of the core exercise member 250 interposed therebetween.

4 is an exploded view showing an artificial disc according to an embodiment of the present invention, and FIG. 5 is an exploded cross-sectional view taken along the line V-V' of FIG. 4 .

4 and 5 , the artificial disk 100 according to an embodiment of the present invention includes a first plate 110 installed in contact with the first vertebrae 1 , and a first plate 110 installed in contact with the second vertebrae 3 . The second plate 170 and the first and second plates 110 and 170 to be installed may include a core movement member 250 installed between.

The first plate 110 is provided with at least one first fixing protrusion 115 having one surface in contact with the first vertebrae 1 and formed on one surface to prevent separation, and the other surface of the first receiving groove 111 is can be formed. In detail, the first fixing protrusion 115 is formed in the upper side of the first plate 110 to prevent the artificial disk 100 from being separated from the first and second vertebrae (1) and (3). can

Here, the first accommodating groove 111 may be formed to be spaced apart from a pair of semi-circles at a predetermined interval and may have a concave curved surface. For example, the first accommodating groove 111 may have a groove shape such as a concave concave toward the inner center. The function of the concave curved shape of the first receiving groove 111 may buffer the shock and pressure that the first plate 110 receives from the second plate 170 and the core exercise member 350 during spinal segmentation motion. Meanwhile, the first accommodating grooves 111 may be spaced apart in a semicircle as shown in FIG. 4 and joined therebetween, but may also be formed in a single oval or circular shape. In addition, the depth inside the first receiving groove 111 has a depth of about 0.07 ~ 0.2mm. However, when the corresponding portion exceeds 0.2 mm, the core movement member 350 is deeply seated in the inner center of the first accommodating groove 111 and is immovably fixed or deformed, and when it is less than 0.07 mm, the core movement member 350 The cushioning function of the impact and pressure of the first plate 110 to the may be lost.

In addition, the first accommodating groove may include a semi-circular part 113 and an extension part 117 . Here, the semi-circular portion 113 may have a pair of semi-circular shapes that are formed to be spaced apart from each other at a predetermined interval. The extension portion 117 may be formed to extend at a spaced apart portion between the pair of semi-circular portions 113 .

Here, since the extended part 117 has an elliptical shape and the two-dimensional translational left and right side surfaces are wider than the lower surface of the core motion member 350 , it can be easily fastened in any direction of the lower surface of the core motion member 350 . On the other hand, the extension 117 of the first accommodating groove 111 and the upper and lower sides of the lower surface of the core movement member 350 coincide with each other, so that the core movement member 350 can be tilted and fastened. Therefore, the structure in which the first accommodating groove has the extension part 117 can prevent the core movement member 350 from being separated from being separated even after being fastened to the first plate 110 . In addition, the first plate 110 has a first tool groove 119 having a depth consistent with the tool on both sides to fix a tool for installation on the first and second vertebrae 1 and 3 may include

The second plate 170 is provided with at least one second fixing protrusion 175 having one surface in contact with the second vertebrae 3 and formed on one surface to prevent separation, and a second receiving groove 171 on the other surface. can be formed. Here, the second accommodating groove 171 may be concavely formed in a hemispherical shape. In addition, the second plate 170 further includes a second tool groove 179 having a depth consistent with the tool on both sides to fix the tool for installation on the first and second vertebrae 1 and 3 may include

The core movement member 250 may be positioned between the first accommodating groove 111 and the second accommodating groove 171 . It is possible to reduce the impact and noise while performing a relatively translational motion with respect to the first plate 110 , and may perform a relative rotational motion with respect to the second plate 170 . In detail, the core motion member 250 may include a rotation motion part 255 , a flange part 257 , and a neck part 253 . The rotational movement unit 255 is installed in contact with the second receiving groove 271 , is formed in a curved surface, and can rotate relatively with respect to the second plate 270 .

The flange portion 257 is located on the lower surface of the core moving member 250 , is installed in contact with the first receiving groove 111 , and is relatively translated with respect to the first plate 110 , while the first receiving groove 111 is installed. ), it can prevent separation and reduce impact and noise. The neck part 253 is interposed between the rotational motion part 255 and the flange part 257, and locks it in the first receiving groove 111 so that the flange part 257 can be installed in alignment, and the core motion member 250. It can play a role in reducing the impact during the translational movement of In addition, the neck portion 253 may be locked to the side of the first receiving groove 211 while the flange portion 257 supports the load of the rotational movement portion 255 . That is, the neck portion 253 may serve to balance and support the load as the area of the rotational movement portion 255 has a load greater than that of the flange portion 257 and has a larger area.

Also, the core moving member 250 may be made of ceramics. In particular, as a material applied to artificial teeth, artificial bones, artificial organs, etc., it can be made of ceramic with chemical stability and biocompatibility. For example, fine ceramics, silicon nitride-based ceramics, alumina (Al ₂ O ₂ ), zirconia (ZrO ₂ ), hydroxyapatite (hydroxyapatite, Ca ₁₀ (PO ₄ ) ₆ (OH) ₂ ), TCP (Tricalcium Phosphate), etc. may be included. These ceramics are excellent in biocompatibility, compressive strength and abrasion resistance. In addition, since ceramic has excellent mechanical strength and can improve impact resistance, it has excellent durability. does not cause However, the core movement member 350 is not limited to a ceramic material, and a synthetic polymer material, for example, polyvinyl chloride (PVC, Polyvinylchloride), polypropylene (PP, Polypr-opylene), polyamide (Nylons, Polyamide) , polymethyl methacrylate (PMMA, Polymethylmethacryulate), silicone, ultra-high-molecular polyethylene (UHMWPE), etc., biopolymer materials such as collagen (collagen), polysaccharide and metal materials, for example, stainless steel, Co-Cr alloy, titanium (Ti) and at least one of biocompatible materials such as titanium alloys, shape memory alloys, etc. may be selected and manufactured in various ways.

The core moving member 250 may be made of ceramic. In particular, the rotational part 255 and the neck part 253 may be made of ceramic, and the flange part 257 may be made of a biocompatible synthetic polymer material. In this case, the flange part 257 may be manufactured to be positioned under the core moving member 250 by a method such as thermosetting, injection molding, caulking, or the like. That is, the rotary motion part 255 and the neck part 253 are made of a ceramic material stronger in mechanical strength, and the flange part 257 has durability while buffering the shock and noise caused by the movement between the first plates 110. A more suitable synthetic polymer material can be used. Therefore, the rotational movement part 255, the neck part 253, and the flange part 257 are made of mutually complementary materials to absorb shocks and reduce noise even after installation, so that they can be used for a long time. However, the present invention is not limited thereto, and each of the rotating part 255 , the neck part 253 , and the flange part 257 may be made of the same material.

In addition, the first accommodating groove 111 may further include a separation preventing unit 120 that prevents separation during the translational and rotational movements of the core movement member 250 . The separation prevention part 120 is formed to protrude around the entrance edge of the first accommodating groove 111, and it may be impossible for the flange part 257 accommodated in the first accommodating groove 111 to be separated from the outside as it is horizontally. . Therefore, there is no fear of separation from each other unless the first and second plates 110 and 170 and the core movement member 250 are forcibly removed by applying a strong force after they are assembled.

6 is an exploded view showing an artificial disc according to another embodiment of the present invention, and FIG. 7 is an exploded cross-sectional view taken along line VII-VII' of FIG. 6 .

6 and 7 , the artificial disk 300 according to another embodiment of the present invention includes a first plate 110 , a second plate 170 , a core movement member 350 and a buffer member 357 . may include Here, each of the members of the artificial disk 300 may perform substantially the same configuration, function, and role as they are members having the same reference numerals as described in FIGS. 4 and 5 . Therefore, in order to avoid redundant description, detailed descriptions of members having the same reference numerals will be omitted as they have been described above.

On the other hand, the core movement member 350 of the artificial disk 300 according to another embodiment of the present invention may be contrasted with the core movement member 250 of the artificial disk according to an embodiment of FIGS. 4 and 5 to be described later. . The core movement member 350 is positioned between the first accommodating groove 111 and the second accommodating groove 171 , and the second plate 170 relative to the first plate 110 performs translational and rotational movements. You can exercise to Referring to FIG. 3 , the core movement member 350 may include a translational movement part 353 , a rotational movement part 355 , and a neck part 353 in detail. The translational movement unit 353 is installed in contact with the buffer member 357 and may perform a relatively translational movement with respect to the first plate 110 together with the buffer member 357 . The rotational movement unit 355 is connected to the translational movement unit 353 to be installed in the second receiving groove 171 , and is formed in a curved surface so that the second plate 170 rotates relative to the core movement member 350 . can The neck part 353 is interposed between the translational motion part 353 and the rotational motion part 355, and while the translational motion part 353 supports the load of the rotational motion part 355, it is locked on the side of the first receiving groove 111. (Locking) can be made. That is, the neck part 353 may serve to balance and support the load as the area of the rotational movement part 355 has a load greater than that of the translational movement part 353 and has a wider shape.

The buffer member 357 is installed between the core motion member 350 and the first plate 110, and a third accommodating groove 351 in which the core motion member 350 is in contact with the first plate 110 may be formed. In addition, the first plate 110 relative to the core movement member 350 may serve as a buffer for reducing shock and noise during a relatively translational motion.

The core movement member 350 may be made of ceramic, and the buffer member 357 may be made of a synthetic polymer material. That is, the core movement member 350 is made of a ceramic material having a stronger mechanical strength, and the buffer member 357 has durability and reduces the impact and noise caused by the movement between the core movement member 350 and the first plate 110 . A synthetic polymer material more suitable for buffering may be used. Therefore, since the core movement member 350 and the buffer member 357 are made of mutually complementary materials, they absorb shocks and reduce noise even after installation, so that they can be used for a long time.

The buffer member 357 may be made of a synthetic polymer material to buffer the core movement member 15 by reducing friction caused by impact and noise when the core movement member 15 relatively translates with the first plate 110 . have. Synthetic polymers are, for example, polyvinyl chloride (PVC, Polyvinylchloride), polypropylene (PP, Polypr-opylene), polyamide (Nylons, Polyamide), polymethyl methacrylate (PMMA, Polymethyl-methacryulate), silicone ( Silicon) and supersynthetic high molecular weight polyethylene (Ultra-high-molecular polyethylene; hereinafter UHMWPE) may be prepared by selecting at least one.

The buffer member 357 is not limited to synthetic polymer materials, but is made of biocompatible materials such as polymers such as ultra-high-molecular polyethylene (UHMWPE), and low-friction elastomers such as polyurethane. It can be manufactured in various ways. Here, UHMWPE is a PE resin with a very high molecular weight, and its average molecular weight is about 10 times that of high-density polyethylene. It has high impact strength that is maintained even at cryogenic temperatures, and has the advantage that it does not crack even when a very strong impact (stress) is applied. In addition, it is a material with excellent various mechanical properties such as high melt viscosity, wear resistance, self-lubrication, energy absorption at high stress, and soft deflection temperature. In more detail, the ultra-high-molecular polyethylene (UHMWPE) powder may have a density within 945 as an average value of the results measured according to the immersion method. That is, specifically, it may be appropriate when it is 925 to 945 kg/m 3 . In addition, the tensile stress at yield (σ _y ) is 18 MPa or more, the tensile stress (σ _R ) at judgment is 25 MPa or more, the elongation at elongation (εR) is 250% or more, and the hole impact strength (α _CN ) is 25 to It may have a physical property of 126 kJ/m 2 .

8A is an assembly cross-sectional view illustrating a first embodiment of an artificial disk according to another embodiment of the present invention, and FIG. 8B is an assembly cross-sectional view illustrating a second embodiment of an artificial disk according to another embodiment of the present invention.

Referring to FIGS. 8A and 8B , the first accommodating groove 111 may form an elliptical shape having different diameters on a vertical axis and a horizontal axis. _{That is, the diameter (D 2} ) based on the horizontal axis of the inlet portion of the first receiving groove 111 can be easily installed in any direction on the bottom surface of the buffer member 357 . _{On the other hand, since the diameter (D 1} ) based on the vertical axis of the inlet portion of the first accommodating groove 111 is smaller than the _{diameter of the bottom surface (C 1a} ) of the buffer member 357 positioned in parallel with the first plate 110, FIG. 8b It can be installed at an angle as Therefore, there is an advantage that the separation between the first plate 110 and the buffer member 357 does not separate after installation. In addition, the artificial disc 300 can be used for a long period of time by maintaining its shape so as not to change even when the force received from the movement of the spine after implantation and reducing frictional shock and noise.

The buffer member 357 and the first accommodating groove 111 may satisfy Equation 2 below.

Here, C _1a means the diameter of the bottom surface of the buffer member 357 positioned parallel to the first plate 110, and C _1b is the buffer member 357 obliquely positioned with respect to the first plate 110. means the diameter of the bottom surface forming an angle between the bottom surface of the , D ₂ means a diameter based on the vertical axis of the inlet portion of the first accommodating groove 111, D ₃ is the inlet portion of the first accommodating groove 111 The horizontal axis means the diameter of the reference.

The first accommodating groove 111 may form an elliptical shape having different diameters on a vertical axis and a horizontal axis. _{That is, the diameter (D 3} ) based on the horizontal axis of the inlet portion of the first receiving groove 111 can be easily installed in any direction on the bottom surface of the buffer member 357 . _{On the other hand, the diameter (D 2} ) based on the vertical axis of the inlet portion of the first receiving groove (111) is obliquely smaller than the _{diameter (C 1a} ) of the bottom surface of the buffer member 357 positioned parallel to the first plate (110). can be installed Therefore, there is an advantage that the separation between the first plate 110 and the buffer member 357 does not separate after installation.

On the other hand, _{each of C 1a} and C _1b in Equation 2 is not limited to the artificial disk 300 according to another embodiment, and the flange portion 257 of the artificial disk 100 according to the previously described embodiment is It can also refer to the bottom and bottom diameters.

9 is a front view showing the second plate of the artificial disk according to another embodiment of the present invention.

Referring to Figure 9, the second plate 170 of the artificial disk 300 according to another embodiment of the present invention has a predetermined thickness, the upper portion forms a curved surface, the lower portion forms a translation, the height of one surface of the front It may be larger than the height of one side of the rear. Such a structure allows the second plate 170 to move flexibly along the curved surface of the core exercise member 350 and efficiently distribute the load applied to the core exercise member 350 .

In addition, the artificial disk 300 has a first fixing protrusion 115 and a second fixing protrusion 175 in which a plurality are formed, and the first plate 110 in contact with the first and second vertebrae (1, 3). ) and the second plate 170 may be located on one side of each. The first fixing protrusion 115 and the second fixing protrusion 175 are in a right triangle shape and are easily fastened when fastened in the B direction, but can be prevented from being separated unless a force is forcibly applied to the A. In this case, the interval between the first fixing protrusion 115 and the second fixing protrusion 175 may be arranged to be narrower from A (front) to B (rear). In the radial arrangement of the first fixing protrusions 115 and the second fixing protrusions 175 as described above, the narrow arrangement may have a greater fixing force than the wide arrangement. Therefore, it is easily fastened when fastening from A (front) to B (rear), but it may be difficult to remove without the aid of a separate mechanism when separating from B (rear) to A (front).

10 is a cross-sectional view illustrating a core moving member according to a first modified example of an artificial disk according to an embodiment or another embodiment of the present invention. And Fig. 11a is a cross-sectional view showing a core moving member according to a second modified example of an artificial disk according to an embodiment or another embodiment of the present invention, and Fig. 11b is a plan view showing the rotational movement unit of Fig. 11a. Next, FIG. 12A is a cross-sectional view illustrating a core moving member according to a third modified example of an artificial disk according to an embodiment or another embodiment of the present invention, and FIG. 12B is a plan view showing the rotational movement unit of FIG. 12A.

Referring to FIGS. 10 to 12B , core center members 250 and 350 according to the first to third modifications of the artificial disk 100 and 300 according to an embodiment or another embodiment of the present invention. The rotational movement parts 255 and 355 of the may further include an inlet portion 351 that is formed to be drawn in at least in part. The inlet portion 351 may include a hole 355a formed in the center of the rotational movement portion 355 . Here, the hole 355a may mean a notch, a groove, a through hole, or the like. In addition, it may include a plurality of dimples 355b that are retracted over the entire rotational movement unit 355 , and may include grooves 355c that are linearly retracted on the rotational movement units 255 and 355 . That is, the inlet 351 may further include at least one selected from the hole 355a, the plurality of dimples 355b, and the at least one groove 355c. Accordingly, it is possible to reduce friction between the second receiving groove 171 and the rotary motion parts 255 and 355 and to improve the flexibility of the contact. In addition, by improving the surgical indications and mobility of the spinal segment after transplantation, it can bring about an effect without restrictions on activities of daily life.

Referring to FIG. 10 , the core center members 250 and 350 according to the first modified example of the artificial disks 100 and 300 may further include an inlet 351 . This inlet 351 is a point contact due to a tolerance that occurs when the second receiving groove 171 and the core center member 250 and 350 are assembled or processed, respectively, and when this part is cracked, friction This increase can be prevented. That is, since the hole 355a, which is the inlet 351, is formed in the core center members 250 and 350, surface contact may be achieved, and friction may be reduced compared to the point contact. Therefore, even after the procedure, patients can live without restrictions and discomfort in their daily spinal segment activities.

11A and 11B, in the second modified example of the artificial disk 100, 300 according to an embodiment or another embodiment of the present invention, the rotational movement part 255 of the core movement member 250, 350 ( The 355 may further include a hole 355a located in the center and a plurality of dimples 355b around the hole 355a. The dimple 355b has the same shape as a dimple, which is a small groove formed on the surface of a golf ball, and may have various shapes, such as a circle, a triangle, and a polygon, like the hole 355a. As shown in FIG. 11B , a hole 355a is formed in the center of the rotational movement parts 255 and 355 , and a plurality of dimples 355b such as a hemispherical small groove may be formed in a predetermined radial arrangement around the hole. Therefore, it is possible to reduce friction generated due to the machining tolerance between the receiving groove 171 and the rotational movement parts 255 and 355 and improve the flexibility of the contact. On the other hand, when the spaces between the plurality of dimples 115b are arranged in the rotational movement parts 255 and 355 to have a constant balance, friction when in contact with the second accommodating groove 171 may be further reduced.

12A and 12B, the rotational movement unit 255 of the core movement members 250 and 350 according to the third modified example of the artificial disk 100, 300 according to an embodiment or another embodiment of the present invention. 355 may include a hole 355a formed through the center and at least one groove 355c. The hole 355a may accommodate foreign substances such as worn fine powder generated by friction between the artificial disks 100 and 300 by the motion of the spinal segment. Accordingly, since the inside of the hole 355a accommodates foreign substances and prevents the artificial disks 100 and 300 from escaping to the outside, side effects such as inflammation after the procedure can be reduced.

Meanwhile, the artificial discs 100 and 300 may be immersed in a spinal strengthening agent before installation between the vertebrae 1 and 3 facing each other. In this case, the inlet 351 of the core exercise members 250 and 350 may further include a spinal strengthening agent. For example, the spinal strengthening agent may include various stem cells, drugs, and nucleus pulposus that are accommodated in the inlet 351 to strengthen the lubricating function and the spine.

In particular, the stem cells may include, for example, embryonic stem cells, adult stem cells/tissue-specific stem cells, and induced pluripotent cells (iPSCs).

In addition, the at least one groove 355c may serve as a passage through which the spinal strengthening agent stored in the hole 355a flows, and may be absorbed into the first and second vertebrae 1 and 3 facing each other. At least one of the grooves 355c may be formed in a linear form on a portion formed in a curved surface over one side of the core movement members 250 and 350 . For example, the groove 355c may be linear in four directions from the center. This groove (355c) reduces friction generated due to machining tolerance when the rotational movement part 355 of the core movement member 350 rotates and translates with respect to the second receiving groove 171 and improves the flexibility of the contact. can do it

13 is an enlarged cross-sectional view of an artificial disk according to an embodiment or another embodiment of the present invention showing the main part.

Referring to FIG. 13 , an artificial disk 100 , 300 according to an embodiment or another embodiment of the present invention is provided on the body 10 and the upper portion of the first plate 110 and the second plate 170 , respectively. A coating layer 20 may be included. 6 shows that the coating layer 20 is formed on the upper surface of the body 10 of the second plate 170, that is, on the upper surface in contact with the other vertebra 3 among the vertebrae, but the body 10 of the first plate 110 The coating layer 20 may also be formed on the lower surface, that is, the lower surface in contact with the first vertebra 1 .

The body 10 of each of the first plate and the second plate is a cobalt-chromium-molybdenum alloy metal material, titanium or a titanium alloy, cobalt-chromium alloy, a biocompatible material such as stainless steel, etc. can be manufactured in a variety of ways. In detail, the body 10 may be made of a cobalt-chromium-molybdenum alloy, that is, 19Co28Cr6Mo in the chemical formula. The content of the cobalt-chromium-molybdenum alloy material is 26 to 30% by weight of chromium, 5 to 7% by weight of molybdenum, 0.75% by weight of iron, and 1% by weight of manganese. Within, silicon (Silicon) within 1% by weight, carbon within 0.14% by weight or 0.15 to 0.35% by weight, nickel within 1% by weight, nitrogen within 0.25% by weight and cobalt ( Cobalt) may be included in 55 to 70% by weight.

In addition, one surface of the body 10 in contact with the first and second vertebrae 1 and 3 includes a coating layer 20 coated with at least one of titanium and hydroxyapatite (hereinafter HA). can do.

Titanium coating may mean coating with non-alloyed titanium and titanium-aluminum-vanadium alloy (Formula: Ti-6Al-4V) powder. Specifically, the titanium-aluminum-vanadium alloy powder may contain 3 to 10 wt% of aluminum, 1 to 4.5 wt% of vanadium, 85 to 95 wt% of titanium, and 0.11 to 1.76 wt% of other additives. On the other hand, the HA coating contains 50 to 79 wt% of hydroxyapatite, 0.5 to 5 wt% of β-TCP, 0.5 to 5 wt% of α-TCP, 0.5 to 5 wt% of TTCP, and 0.5 to 5 wt% of CaO 5% by weight and other additives. Also, the thickness of the coating layer may be 0.01 to 0.2 mm. If it is less than the minimum value of 0.01 mm, the coating hardness is low and weak to scratches, and the original purpose of the coating may be lost. In addition, if it exceeds the maximum value of 0.2 mm, the probability of seizure is high and friction may increase during the movement of the core moving part. Accordingly, the biostability of the artificial disk 100 implanted in the first and second vertebrae 1 and 3 by including the above-described coating layer 20 on the body 10 of the artificial disk 100 . , biocompatibility and interfacial compatibility can be improved.

14 is a cross-sectional view showing an operating state in C and D directions of an artificial disk according to an embodiment or another embodiment of the present invention.

14, the artificial disk 100, 300 according to an embodiment and another embodiment of the present invention has a second plate ( 170) can move forward, backward, and left and right. In particular, when considering the anatomical movement of the human body, it is necessary to limit the movement within a specific range. Accordingly, when the second plate 170 flows with respect to the first plate 110 , the range of the internal maximum angle θ therebetween may be 20° to 25°. For example, as shown in Fig. 8a, when the second plate 170 is in contact with the first plate 110 in the C direction when viewed from the front portion (A) of the treated patient, the inner maximum angle in the D direction ( θ) may range from 20° to 25°. As such, when contacting in the opposite D direction, the range of the inner maximum angle θ in the C direction may be the same.

On the other hand, in the case of a conventional artificial disc having an internal maximum angle θ of 5.77° to 9.02° of the flow angle of the second plate 170 with respect to the first plate 110, the segmental motion of the patient's spine after implantation is restricted and segmentation There was a limit to feeling uncomfortable during exercise. On the other hand, when the second plate 170 flows with respect to the first plate 110, the range of the internal maximum angle θ therebetween is 20° to 25°. There are no restrictions on activities of daily life.

In addition, the artificial disc 100 , 300 has a buffer member 357 located in the first receiving groove 111 when the second plate 170 is in contact with the first plate 110 in the C or D direction. It can translate in the opposite D or C direction. The translational movement of the cushioning member 357 may have the effect of preventing the separation of the core moving part 350 from the second plate 170, alleviating the impact, and reducing the noise.

Accordingly, more preferably, the inner maximum angle θ in the C and D directions is 20.1° and the inner maximum angle θ in the A and B directions is 24.3°. Therefore, it is possible to minimize the load while allowing the load applied to the core movement unit 350 to be evenly distributed. In addition, in consideration of the anatomical movement of the human body, the range of the internal maximum angle (θ) is limited to 20° to 25°, and the movement center of the human body and the center according to the movement of the artificial disk 100 are mutually rapidly can be made to match. That is, it is possible to minimize the load applied to the artificial disk 100 by dispersing the stress acting on the spine due to the discontinuous movement according to the mismatch of the upper and lower vertebrae.

15A is a plan view showing an artificial disk further including an elastic band according to an embodiment or another embodiment of the present invention, and FIG. 15B is a side cross-sectional view showing FIG. 15A from the side.

15, a band that surrounds the first plate 110 and the second plate 170 and prevents separation from each other, limits the movement of the core movement members 250 and 350 and restores the initial position. It may further include at least one elastic member 400 formed of. The elastic member 400 may be made of at least any one group of silicone and polycarbon urethane with bioimplantation compatibility, and avoiding the positions of the first fixing projections 115 and the second fixing projections 175 having a radial arrangement. It can be bent in an 'X' shape in an area that can be secured. That is, the elastic member 400 can freely move each of the first plate 110 , the second plate 170 , and the core movement member 250 , 350 while limiting the range of departure so as not to be separated from each other at the same time. Therefore, it can be used for a long time. However, it is not limited to bending in the above shape, and may be bent around the outside of the first and second plates 110 and 170 in various shapes such as '+' and 'Y'.

16 is a plan view (a) and a side cross-sectional view (b) of an artificial disc according to another embodiment of the present invention.

The artificial disk according to another embodiment of the present invention may further include movement limiting units 552 and 722 in each of the first plate 710 and the core movement member 550 . The movable limiting units 552 and 722 may be located in a horizontal length of the first plate 710 among the edges of the first accommodating groove 711 . In addition, to be located in at least one of the flange portion 557 and the buffer member 357 of the core movement member 550 facing the transverse length, the core movement member 550 from the first plate 710 is horizontal Projections or grooves may be formed to limit or impede translational and rotational motion in length. Referring to FIG. 16 , the core movement member 550 is a portion indicated by a dotted line, and flange portions 557 are formed at both ends of the longitudinal length, and the movable limiting portions 552 formed flat at both ends of the horizontal length may be included. A solid line drawn on the inside based on the dotted line indicates the outside of the first plate 710, and the first plate 710 has a separation prevention part ( 720) is included, and a movement limiting unit 722 for limiting the left and right movement of the core movement member 550 may be included at both ends of the transverse length. As shown in the sectional side view (b) of FIG. 16 , each of the separation preventing part 720 and the movable limiting part 722 of the first plate 710 is the flange part 557 and the movable limiting part of the core moving member 550 . For accommodating each of the portions 552 to prevent separation or to limit movement, it may be formed to protrude further. On the other hand, the dotted line drawn on the outside based on the dotted line of the core motion member 550 indicates the first receiving groove 711 inside the first plate 710, and the first plate 710 is at both ends of the longitudinal length. The flange portion 557 of the core motion member 550 is accommodated to secure a free space with a movable range capable of translational and rotational motion in A and B directions, and the core motion member 550 is inclined in the space. Easy to install and assemble. In addition, the first plate 710 has a movable limiting portion 552 of the core movement member 550 is accommodated at both ends of the horizontal length, so there is a free space equivalent to the tolerance at the time of assembly, but the space has a movable range in which it can move freely. can be limited It is not limited to the above-described movable limiting units 552 and 722 , and each of the first plate 710 and the core moving member 550 may further include at least one stud or recess.

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: 1st vertebra 3: 2nd vertebra
5: nerve root 7: vertebral arch
9: spinal cord 10: body
20: coating layer 100, 300: artificial disc
110, 710: first plate 111, 711: first receiving groove
113: semicircular part 115: first fixing process
117: extension 119: first tool groove
120, 720: separation prevention unit 130: buffer member
131: third receiving groove 170: second plate
171: second receiving groove 175: second fixing projection
179: second tool groove 250, 350, 550: core movement member
253, 353, 553: neck part 255, 355: rotational movement part
257, 557: flange portion 351: inlet portion
355: rotational movement 355a: hole (hole)
355b: dimple 355c: groove
357: translational movement 400: elastic member
552, 722: movable limiting unit AD: conventional artificial disc
CL: Centerline D: Disc

Claims (7)

In the artificial disc installed between the first vertebrae and the second vertebrae respectively located in the lower and upper parts,
A first plate that is installed on the upper portion of the first vertebra and is formed on one surface in contact with the first vertebra and has at least one first fixing protrusion for preventing separation, the first plate having a first accommodating groove on the other surface thereof; ;
It is installed on the lower part of the second vertebrae so as to face the first plate and spaced apart from the first plate, and has at least one second fixing protrusion formed on one surface in contact with the second vertebra to prevent separation, and on the other surface a second plate on which a second receiving groove is formed; and
It is located between the first accommodating groove and the second accommodating groove, and reduces shock and noise while performing a relative translational motion with respect to the first plate, and includes a core moving member that rotates relative to the second plate. and
Each of the first plate and the second plate,
_{It has a length difference (L g} ) drawn into the front (A) between _{the length (L 1} ) from the center line (CL) to the rear end of the first plate _{and the length (L 2} ) to the rear end of the second plate Even if the first and second vertebrae move backward (B), an artificial disc, characterized in that it does not interfere with the nerve roots. According to claim 1,
The core movement member,
a rotational movement part installed in contact with the second receiving groove and formed in a curved surface to rotate relative to the second plate;
A plan that is located on the lower surface of the core moving member, is installed in contact with the first accommodating groove, and prevents separation within the first accommodating groove and reduces shock and noise while performing a relative translational motion with respect to the first plate chapter; and
Interposed between the rotary motion part and the flange part, it locks in the first accommodating groove so that the flange part can be installed to be matched, and it characterized in that it comprises a neck part for reducing shock and noise during translational motion of the core moving member. artificial disc. According to claim 1,
The core movement member,
It is installed between a portion of the core moving member and the first plate and a third accommodating groove is formed therein, and the first plate relative to the core moving member is a buffer that relieves shock and noise during translational motion. Artificial disc, characterized in that it further comprises a member. 4. The method of claim 3,
The core movement member,
a translational movement unit installed in contact with the buffer member and performing a relative translational motion with respect to the first plate together with the buffer member;
a rotational movement part connected to the translational movement part and installed in the second receiving groove, the rotational movement part being formed in a curved surface so that the second plate rotates relative to the core movement member; and
The artificial disk, which is interposed between the translational motion part and the rotational motion part, further comprising a neck part to be locked to the side of the first receiving groove while the translational motion part supports the load of the rotational motion part. According to claim 1,
The first plate and the second plate,
An artificial disc, characterized in that it satisfies the following conditional expression 1.
<Condition 1>

Here, L ₁ is the length from the center line CL of the first plate 110 to the rear end of the first plate 110, and L _g is the rear of the second plate 170 from the center line CL. It means the difference in length leading to the front (A) between the length to the end (L ₂ ) and L _{1 .} 6. The method according to any one of claims 1 to 5,
Surrounding the first plate and the second plate, preventing separation from each other, limiting the movement of the core movement unit and at least one elastic member formed as a band to be restored to the initial position artificial disk, characterized in that it further comprises . 6. The method according to any one of claims 1 to 5,
On each of the first plate and the core moving member,
To be located in at least one of the flange portion and the cushioning member of the core moving member located in the horizontal length of the first plate or facing the horizontal length of the edge of the first accommodating groove, the first plate The artificial disk, characterized in that it further comprises a movable limiting part, characterized in that the protrusion or groove is formed so as to limit or prevent the translational and rotational movement of the core moving member in the transverse length.

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