KR101276183B1 - Pedicle screw assembly - Google Patents

Abstract

The present invention relates to a pedicle screw used to fix a bone such as a vertebra. The pedicle screw is connected to the rod and is fixed to the bone. The pedicle screw has a head having an upper surface recessed to form a head groove and a seating hole formed on a bottom surface of the head groove, a seating head And a screw having a screw portion connected to a lower end of the seating head and threaded to be fastened to the bone, and a pin arranged to cross the seating head and the head, So as to be rotatable. According to the present invention, the movement of the head relative to the screw can be limited to the rotation about the short axis, so that the operation can be made more flexible than the monoscrew method, and the fixing force can be secured much superior to that of the screw method.

Description

Pedicle screw assembly}

The present invention relates to a pedicle screw used to fix a bone such as a vertebra.

Generally, spinal diseases include disc herniation (spinal disc) and scoliosis. Among these vertebral diseases, scoliosis is a disease in which the vertebrae bend and twist like a pretzel, and if left untouched, the deformation of the vertebrae continues to progress, eventually leading to severe deformity of the vertebra bone, Of complications. Such scoliosis can be treated through the use of an orthosis or surgery depending on the angle of flexion of the vertebrae bones.

In such a variety of spinal diseases, a surgical method for restoring a bent vertebra to a circular shape is called a pedicle screw insertion, which is performed by inserting a screw into a bent vertebra bone. This is a way to help the vertebrae recover to its normal state by inserting the pedicle screws into the curved vertebrae and connecting the pedicle screws to each other using rods.

The pedicle screws used in this pedicle screw insertion are generally mono-screw type, in which the angle between the head and the screw is fixed, A poly screw system has been used which is provided so as to be able to vary the angles to be formed.

In the case of the monoscrew method, although the fixation force is excellent, since the head is fixed to the screw constantly, if the screw is inserted in the wrong direction to the vertebra bone at an early stage, the rod and the head are later shifted, There is a problem that it becomes difficult.

On the other hand, in the case of the polyscrew system, even if the screw is initially inserted in the wrong direction of the vertebrae, there is an advantage in that the head can be flexibly adjusted so as to facilitate the insertion of the rod through various movements of the head. However, It is disadvantageous in that the fixing force is insufficient as compared with the mono screw.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to solve the above-mentioned problems, Thereby providing a screw.

According to an aspect of the present invention, there is provided a pedicle screw screw connected to a rod and fixed to a bone, the pedicle screw having an upper surface recessed to form a head groove, A mounting head mounted on the periphery of the mounting hole, a screw connected to a lower end of the mounting head and having a screw thread formed to be fastened to the bone, and a positioning member disposed across the mounting head and the head And the mounting head is provided with a curved side surface so as to be rotatable about the pin.

The side surface of the seating head may be provided with a curved surface having a radius of curvature centering on the fin.

Wherein the seating head includes a seating head pin hole extending in the lateral direction and a head pin hole communicating with the seating head pin hole at both sides of the head, And may be disposed in the head pin hole and the seating head pin hole.

The pedicle screw according to an embodiment of the present invention may further include a friction member whose lower surface is engaged with the upper side of the side surface of the seating head and whose upper surface is in contact with the rod.

The mounting head may have a fastening groove formed at an upper end of the fastening head so as to engage with a fastening mechanism for fastening the screw, and the friction member may have a ring shape with a central portion thereof being opened to expose the fastening groove.

The rod may be disposed across the head, and the pin may be disposed in a direction perpendicular to the rod.

On both sides of the head, a rod groove is formed in a U-shape so that the rod can be disposed, and a screw thread can be formed on the inner circumference of the head groove so that a fastening unit for fastening and fixing the rod downward can be fastened .

The pedicle screw according to an embodiment of the present invention may further include a fixed unit that is fastened to the inner circumference of the head groove so as to press and fix the rod downward.

According to the present invention, it is possible to limit the movement of the head with respect to the screw to the rotation about the short axis by providing the pin which crosses the head and the mounting head of the screw, so that the operation can be performed more flexibly than the monoscrew method, It is possible to secure a fixing force that is much superior to that of the conventional method.

Further, since the frictional member is provided between the rod and the seating head, the contact area between the friction member and the seating head is large, so that the pressing force transmitted from the rod can be applied with a greater frictional force, .

1 is a perspective view of a pedicle screw according to an embodiment of the present invention.
Fig. 2 is a three-dimensional view showing a section taken along the line II-II in Fig.
3 is a perspective view of a screw of a pedicle screw according to an embodiment of the present invention.
FIG. 4 is a cross-sectional view taken along line II-II of FIG. 1, showing a state where a rod is fixed to a pedicle screw according to an embodiment of the present invention.

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

For reference, the terms related to directions (top, top, upward, downward, downward, bottom, and lateral directions) in the description of the present invention are set based on the arrangement state of each structure shown in the drawings. Illustratively, in FIGS. 1 to 4, the downward direction is downward and the upward direction is upward. In addition, the transverse direction can mean one of various directions on a plane perpendicular to the up-and-down direction when viewed in Fig. For example, as viewed in Fig. 4, the left-right direction may be the lateral direction, and the front-rear direction (front-back direction) may be the lateral direction. However, in various applications of the pedicle screw according to an embodiment of the present invention, the pedicle screw is positioned in the lower left direction, such as the position and angle of insertion with respect to the bone, such as the vertebrae, In various directions.

A pedicle screw 100 according to one embodiment of the present invention (hereinafter referred to as 'the present pedicle screw') relates to a pedicle screw connected to a rod 600 and fixed to a bone such as a vertebra. Although the vertebral pedicle screw 100 is mainly applied to fix the vertebrae bone to treat a spinal disease, the scope of the present invention is not limited thereto, and the vertebrae 100 can be variously applied to the bones other than the vertebral bone. Hereinafter, the construction of the pedicle screw 100 will be described.

The pedicle screw 100 includes a head 1.

4, when a screw 2 to be described later is inserted and fixed to a bone such as a vertebra, the head 1 is fastened with the rod 600 across the head 1 (E.g., by pressurization of the pressing member 5). That is, in this pedicle screw 100, the head 1 is a portion connected to the rod 600. A plurality of the vertebral column screws 100 are inserted into predetermined positions of the curved vertebrae and the rods 600 are fastened to the head 1 of each pedicle screw 100 to form the respective pedicle screw 100 ), So that the vertebrae can be calibrated to the normal state.

More specifically, referring to Figs. 1, 2, and 4, an upper surface of the head 1 is depressed to form a head groove 11. As shown in Figs. 1 and 2, the rod grooves 14 may be formed in a U-shape so that the rod 600 is disposed on both sides of the head 1. [ That is to say, the rod 600 can be arranged to cross the head 1 through the above-described head groove 11 and the U-shaped rod groove 14 formed on both sides of the head 1 .

Referring to FIGS. 1, 2 and 4, a thread 113 is formed on the inner circumference of the head groove 11, to which a fixing unit 5 for pressing and fixing the rod 600 downward can be fastened . 4, the fixing unit 5 is screwed to the thread 113 of the head groove 11 and is screwed to the outer circumference of the head groove 11 so as to be gradually moved in the vertical direction 113 having a thread to engage with the screw. That is, by moving the fixed unit 5 downward gradually by tightening it, the rod 600 under the rod 600 can be pressed downward to fix the rod 600.

In addition, the present pedicle screw 100 may include a fixed unit 5. The fixed unit 5 can be fastened to the inner circumference of the head groove 11 so as to function to push down and fix the rod 600 downward. The fixing unit 5 may be in the form of a screw as described above, but it is not limited to this type. The fixed unit 5 can be provided with one of various mechanisms or devices capable of gradually pushing down the rod 600 and the inner circumference of the head groove 11 can be provided with a mechanism Or may be formed in a shape corresponding to the shape of the apparatus.

A seating hole 12 is formed in the bottom surface of the head groove 11. A screw 2 as shown in Fig. 3 is inserted into the seating hole 12 as shown in Figs. 1 and 2, so that the seating head 21 can be seated in the seating hole 12. Fig.

2 and 4, outer grooves 15 may be formed on both outer side surfaces of the head 1. This is a groove for engagement with a mechanism such as a rod pershader for fully securing the rod 600 to the head 1 later.

The present pedicle screw 100 includes a screw 2.

Referring to FIG. 3, the screw 2 includes a seating head 21 and a threaded portion 22.

The seating head 21 is seated around the seating hole 12. 2, the maximum width of the seating head 21 is slightly larger than the width of the seating hole 12 formed in the bottom surface of the head groove 11, And can be seated around. 2, the seating head 21 has a sidewall shape and is formed with a seating hole 12 smaller than the diameter thereof, so that the seating head 21 is seated around the seating hole 12 .

However, the seating head 21 may not be seated directly against the periphery of the seating hole 12. That is, the seating head 21 is not in direct contact with the periphery of the seating hole 12, but a pin 3 to be described later is arranged to cross the seating head 21 and the head 1, And may be seated on the seating hole 12 through the pins 3 supported at both ends thereof. Or the seating head 21 may be seated around the seating hole 12 in such a manner that the seating head 21 directly contacts the periphery of the seating hole 12 and is simultaneously supported by the head 1 via the pin 3. [ In other words, the fact that the seating head 21 is seated around the seating hole 12 means not only the seating by the direct contact but also the indirect seating through the pin 3.

2 to 4, the threaded portion 22 is connected to the lower end of the seating head 21, and the threaded portion 22 is fastened to a bone such as a vertebra, A thread 221 is formed.

2 and 3, a fastening groove 212 may be formed at the upper end of the seating head 21 so as to engage with a fastening mechanism (not shown) for screwing the threaded portion 22 . As shown in FIG. 3, the fastening groove 212 may be a groove that is recessed in a cross shape when viewed from above, and a corresponding screw driver mechanism may be applied as a fastening mechanism in correspondence with the fastening mechanism and the fastening groove 212 .

In addition, the pedicle screw 100 includes a pin 3.

The pin (3) is arranged to cross the seating head (21) and the head (1).

2 and 3), the seating head pin hole 211 described above is formed on both sides of the head 1, and the seating head pin hole 211 is formed on both sides of the head 1, And the head pin hole 13 can be made to communicate with each other (refer to FIG. 1 and FIG. 2). That is, the pins 3 may be disposed in the head pin hole 13 and the seating head pin hole 211 such that both sides of the pin 3 are respectively supported by the head pin hole 13. In other words, the pin 3 relatively rotatably connects the head 1 and the screw 2 through the holes 13 and 211.

Among the existing pedicle screws, the monoscrew method has a good fixing power, but it has a disadvantage that the rod can not be fastened even if the insertion direction of the screw is slightly deviated. In the case of the polys screw type, the head can be adjusted at various angles with respect to the screw, It has a disadvantage in that the fixing force is greatly lowered. On the other hand, the pedicle screw 100 includes the pin 3 which crosses the head 1 and the seating head 21 of the screw 2, so that the movement of the head 1 is restricted to only one axis So that the ease of operation can be ensured and the fixing force can be realized much better than that of the poly screw.

1, 2 and 4, the head pin hole 13 may be formed to be larger than the diameter of the pin 3, and the seating head pin hole 211 may be formed in the pin 3, As shown in FIG. The head pin hole 13 formed on the outer side is formed to be somewhat larger than the pin 3 so that the pin 3 can be assembled and the pin 3 and the screw 2 can be easily adjusted. The mounting head pin hole 211 formed in the mounting head 21 of the screw 2 is formed to have a size corresponding to that of the pin 3 so that the rotation of the screw 2, Can be stably performed without shaking.

However, the height of the head pin hole 13 may be formed to be larger than the diameter of the pin 3, and the width of the head pin hole 13 may be formed to correspond to the diameter of the pin 3. Even if the height of the head pin hole 13 is made larger than the diameter of the pin 3, the movement of the pin 3 is limited through downward movement and pressing of the fixed unit 5 and the rod 600 (Upward and downward in FIG. 4) of the head pin hole 13 can be moved to some extent before the fixing between the head 1 and the screw 2 is performed through such pressing It is preferable that the height of the head pin hole 13 is larger than the diameter of the pin 3 from the viewpoint of ease of assembly of the pin 3 and adjustment of the pin 3 and the screw 2. [

The seating head 21 of the lifting screw 2 is provided with a curved side surface so as to be rotatable about the pin 3. Illustratively, as shown in Fig. 3, the side of the seating head 21 may be spherical. Since the side surface of the seating head 21 may be curved at a line that can rotate about the pin 3, the side surface of the seating head 21 is not limited to a sphere, That is, only the side surface corresponding to the rotation circumference when the seating head 21 is rotated about the pin 3, may be a curved surface. However, the screw 1 is not rotated only about the axis 3, but it must be smoothly rotated about the longitudinal direction of the screw 2 in order to be screwed to a bone such as a vertebra. It is preferable that the side surface of the head 21 is generally curved (for example, spherical) as shown in Fig.

Further, in the rotation about the pin 3, it is most advantageous to minimize the friction or interference by making the side surface of the mounting head 21 a curved surface having a radius of curvature with the pin 3 as the center. That is, the side surface of the seating head 21 may be provided as a curved surface having a radius of curvature centering on the pin 3. [

As previously noted, the rod 600 is disposed across the head 1, which is preferably disposed in a direction orthogonal to the rod 600, as shown in FIG.

Illustratively, when inserting a plurality of the vertebral column screws 100 at predetermined angles of the bent vertebrae respectively, each insertion is performed in consideration of the arrangement of the rods 600. [ Incidentally, in the insertion of each of these pedicle screws 100, it may happen that some of the plurality of pedicle screws 100 do not correspond to the arrangement of the rod 600, depending on the situation. 4, when the rod 600 does not accurately cross the portion of the rod groove 14 of the head 1 of the spinal screw 100 and is biased to the left or right side 1 and the rod 600 cross the part of the rod groove 14 of the head 1 of the pedicle screw 100 is tilted upward or downward so that the rod 600 moves in the head 1 (Situation 2) may occur.

However, as in Situation 2, a slight angular difference between the head 1 and the rod 600 may be more easily generated depending on the condition of the bone, the procedure, and the like. That is, the angle of the head 1 needs to be adjusted flexibly in accordance with the degree of inclination of the rod 600 in the longitudinal direction thereof. As shown in FIG. 4, The head 1 can be rotated in accordance with the degree of tilting of the rod 600 in the longitudinal direction by using the pin 3 as a rotation axis.

The present pedicle screw 100 may include a friction member 4.

Referring to Figs. 2 and 4, the friction member 4 has its lower surface engaged with the upper side of the side surface of the seating head 21 and its upper surface brought into contact with the rod 600. Fig. Illustratively, as shown in FIGS. 1 and 2, the friction member 4 may be in the form of a ring having a central portion through which the fastening groove 212 of the seat head 21 is exposed upwardly. Since the friction member 4 is provided in a ring shape, the fastening mechanism can be easily coupled to the fastening groove 212.

4, when the friction member 4 is not provided, the rod 600 is pressed downward and the seating head 21 is directly pushed downward. The rod 600 and the seating head 21 A large frictional force can not be generated because the contact area is small, so that the fixing force to the screw 2 can be secured to be somewhat small. However, when the friction member 4 is provided as shown in FIG. 4, the rod 600 is pressed downward to push the friction member 4 downward, and the friction member 4 directly contacts the seat head 21 As shown in FIG. That is, when the friction member 4 is provided, since the contact area between the friction member 4 and the seating head 21 is large, the pressing force transmitted from the rod 600 can act as a larger frictional force, The fixing force to the base 2 can be secured to a much greater extent.

2 and 4, a rim 112 may be formed on the inner circumference of the head groove 11 of the head 1 to limit the upward movement of the friction member 4. As shown in FIG. By forming the jaws 112, the friction member 4 can be prevented from being easily separated from the head groove 11 when the rod 600 is not fastened to the head 1.

Hereinafter, the operation between the above-mentioned angular configurations will be briefly described with reference to Figs. 1 to 4 mainly with reference to Fig.

First, check the position and angle of screwing the pedicle screws (100) on the vertebrae. Next, after the fastening mechanism is engaged with the fastening groove 212 of the screw 2 of the present vertebra thread screw 100 in which the pin 3 is not yet inserted, the vertebral thread screw 100 is moved to the position and position Tighten the screws according to the angle. Next, the pin 3 is inserted through the head pin hole 13 and the seating head pin hole 211. Next, the rod 600 is appropriately disposed on the head 1 while adjusting the head 1 by rotating the pin 3 about its axis. Next, the fixed unit 5 is mounted on the upper side of the head groove 11 on which the screw thread 113 is formed, and is then moved downward to gradually push the rod 600. The rod 600 transmits a pressing force received from the fixed unit 5 to the friction member 4 and the friction member 4 presses the upper side of the seating head 21 of the screw 2 through this pressing force. Since the lower surface of the friction member 4 and the upper surface of the side surface of the seating head 21 are engaged with each other with a wide contact area by the pressing of the friction member 4 and the screw 2 is moved with respect to the head 1, A large frictional force is generated with respect to the contact area to prevent such movement.

As described above, according to the present invention, the head 1 can be shortened and adjusted with respect to the screw 2 with respect to the pin 3, and the rod 600 can be more easily arranged on the head 1. In addition, since the head 1 can rotate only with respect to the screw 2, it is easy to secure the fixing force, and the pressing force transmitted through the rod 600 through the friction member 4 can be applied to a greater frictional force A very large fixing force can be secured easily.

The seating head 21 may be provided to be larger than the width of the seating hole 12 so as to be brought into direct contact with the periphery of the seating hole 12 and may be seated. Or may be mounted indirectly through the support by the pin 3. In this case, the width of the seating head 21 may be smaller than or equal to the width of the seating hole 12, and the seating head 21 may pass through the seating hole 12 only if the pin 3 is not inserted. have.

In this case, the screw 2 separately separated from the head 1 is fastened to the vertebra bone first and then the positioning head 21 is passed through the seating hole 12 to place the head 1 on the screw 2 The process of inserting the present pedicle screw 100 into the vertebra bone may be performed by assembling the pedicle screw 3 and then inserting the pin 3 into the holes 13 and 211 (the same process as described above).

The seating head 21 is engaged with the lower surface of the friction member 4 when the seating head 21 is passed through the seating hole 12 to assemble the head 1 to the screw 2, The upward movement of the friction member 4 is restricted by the jaws 112 formed on the inner periphery of the head 1 and the head 1 may not be moved further upward so that the assembling is performed through the jaws 112 Can be facilitated.

While the present invention has been particularly shown and described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, And all changes and modifications to the scope of the invention.

100. Pedicle screw
1. Head 11. Head groove
112. Jaw 113. Threaded
12. Mounting hole 13. Head pin hole
14. Rod groove 15. Outer groove
2. Screw 21. Seat head
211. Mounting head pin hole 212. Tightening groove
22. Thread 221. Thread
3. Pin 4. Friction member
5. Fixing unit 600. Load

Claims (8)

A pedicle screw connected to the rod and secured to the bone,
A head in which an upper surface is recessed to form a head groove and a seating hole is formed in a bottom surface of the head groove,
A screw having a seating head that is seated around the seating hole and a threaded portion that is connected to a lower end of the seating head and is threaded to be fastened to the bone,
A pin disposed to cross the seating head and the head;
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Wherein the seating head has a curved side surface so as to be rotatable about the pin,
Wherein a side surface of the seating head is provided with a curved surface having a radius of curvature centering on the pin. delete The method of claim 1,
The seating head is provided with a seating head pin hole in the lateral direction,
And a head pin hole is formed at both sides of the head so as to communicate with the seating head pin hole,
Wherein the pin is disposed in the head pin hole and the seating head pin hole such that both sides of the pin are respectively supported by the head pin hole. The method of claim 1,
Further comprising a friction member which is engaged with an upper side of a side surface of the seat and whose upper surface is in contact with the rod. 5. The method of claim 4,
Wherein a fastening groove is formed in an upper end of the seating head, the fastening groove being engageable with a fastening mechanism for screwing the screw,
Wherein the friction member has a ring shape having a central portion through which the fastening groove is exposed to the upper side. The method according to any one of claims 1 to 5,
The rod being disposed across the head,
Wherein the pin is disposed in a direction orthogonal to the rod. The method of claim 6,
Rod grooves are formed in both sides of the head in a U-shape so that the rod can be disposed,
Wherein a threaded portion is formed on an inner circumference of the head groove so that a fixed unit for pressing and fixing the rod downward can be fastened. The method of claim 6,
And a fixing unit which is fastened to the inner circumference of the head groove so as to press and fix the rod downward.

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