KR20020078616A - Fixing system for spine - Google Patents

Abstract

PURPOSE: A fixing system for spine is provided to assemble easily a spine fixing system by improving a connecting structure between a rod for connecting each spine to each other and a pedicle screw transplanted to a spinal column. CONSTITUTION: A pedicle screw(31) has a head(32). A saddle(34) is formed in a lower portion of an inside of the head(32). A rod(36) is arranged on an upper portion of the saddle(34). An interface locker(37) is contacted with the rod(36). A set screw(38) is combined with the interface locker(37). The set screw(38) is combined with a spiral portion(33) formed on an inner surface of the head(32). A ring(41) is combined with an upper portion of the head(32). The head(32) is formed with two branch parts(32a,32b). The spiral portion(33) is formed on inner surfaces of the branch parts(32a,32b). A projection(32c) is formed on an outer surface of the branch parts(32a,32b). A passing hole(32d) is formed on the branch parts(32a,32b), respectively. An upper portion of the saddle(34) is formed with a curve portion(34a). A pin insertion groove(35) is formed at both sides of the saddle(34). A pin(42) is inserted into the pin insertion groove(35) of the saddle(34). A caulking portion is formed on an upper portion of the interface locker(37). A lower portion of the interface locker(37) is formed with a curve portion(37a).

Description

Fixing system for spine

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spinal fixation device, and more particularly, to a spinal fixation device having an improved connection structure between a rod connecting an individual spine and a pedicle screw implanted into a vertebra.

The spinal fixation device is a device for treating a patient whose abnormality has occurred in the spine due to some cause by surgery. For example, in a patient with a vertebral fracture, the vertebrae of the vertebrae are interconnected through a vertebral fixation device to help the vertebrae return to normal. The patient will live permanently with the implanted spinal fixture.

1 is an example of a spinal fixation device according to the prior art, which is disclosed in Korean Patent Registration No. 148800.

Referring to the drawings, the spinal fixation device is a conical screw (2) having a head (4) formed at the top, a ring (9) is fitted to the rod (6) inserted into the head (4). The ring 9 is formed on its outer surface as part of a sphere. A locking screw 7 is engaged in the head 4 to prevent the ring 9 from disengaging from the head 4. The lower end of the locking screw 7 is in contact with the outer circumferential surface of the ring 9 in a pressurized state to prevent the rod 6 from being separated from the ring 9. In addition, the cap 8 is covered on the upper outer circumferential surface of the rod 4 to prevent the locking screw 7 from being detached.

In the spinal fixation device having the above configuration, the conical screw 2 is implanted by screwing against the vertebra of the patient. One conical screw 2 is connected via the rod 6 with another conical screw coupled to the other vertebra. In this case, the rod 6 should be adapted to have an appropriate curvature according to the shape of the spine of the individual patient. Such a deformation of the rod 6 may be made by using a predetermined instrument at the implantation site. The patient can prevent further spinal damage by the spinal fixation device and remain stable until the condition of the vertebrae improves.

The ring 9 fitted to the rod 6 is in point contact with the surface of the rod 6, so that the rod 6 can tilt in the predetermined range with respect to the head 4. That is, even if the state of flexion of the spine changes in accordance with the motion of the spine, the rod 6 can accommodate the change in the state of flexure of the spine because the rod 6 is allowed to change the angle with respect to the head 4 within a predetermined range. will be.

Spinal fixation device having the above structure has the following problems. First, when the rod 6 is excessively inclined with respect to the head 4, the engagement of the ring 9 and the locking screw 7 is likely to be imperfect. Second, the assembly of the cap 8 is not easy during the procedure. That is, since the cap 8 is held in place by the force of the two parts where the head 4 is split, the cap 8 at the top of the head 4 which is already opened due to the fastening of the locking screw 7. ), The frictional resistance becomes severe. Third, there is a possibility that parts such as rings 9 are lost during the procedure.

2 is a schematic cross-sectional view of another spinal fixation device according to the prior art, which is disclosed in Korean Patent Publication No. 2000-6777.

Referring to the drawings, a head 12 is formed at an upper portion of the screw portion 11, and a locking ring 13 is provided at a lower portion of the head 12. The inner circumferential surface of the locking ring 13 is formed as part of a spherical shape, and the lower pivot 14 is coupled to the spherical inner surface in a rotatable state. As shown in the drawing, the lower pivot portion 14 is pivotable on the inner circumferential surface of the locking ring 13 because the lower portion is formed of a sphere, and the upper surface is a corresponding surface capable of making surface contact with the curved surface of the rod 15. Formed.

On the other hand, the top of the head 12 is fixed cap 16 is installed, the upper pressing portion 17 is installed inside the fixed cap 16. The inner circumferential surface of the upper pressing portion 17 is formed as a curved surface that can correspond to the outer surface of the sphere, and the upper rotating portion 18 is provided in the upper pressing portion 17. As can be seen in the figure, the upper pivot 18 has an outer surface that is generally spherical in shape so as to be able to pivot in the upper press 17, and the lower surface is in surface contact with the rod 15. It has a surface.

In the spinal fixation device having the above configuration, the screw 11 is screwed to the vertebra, and the rod 15 is fixed in a pressurized state between the upper pivot 18 and the lower pivot 14. As described above, the upper pivot 18 may be pivoted in the upper press 17 and the lower pivot 14 is pivotable in the engagement ring 13, so that the rod 15 It can be tilted relative to the head 12 within the range.

The spinal fixation device described with reference to FIG. 2 requires a relatively large number of parts, is not easy to manufacture the parts and the coupling between the parts, there is a disadvantage in that even in the field of application. For example, the mutual coupling of the upper pivot 18 and the upper press 17 and the mutual coupling of the lower pivot 14 and the locking ring 13 should be made in an interference fit method, which is not easy. .

The present invention has been made to solve the above problems, it is an object of the present invention to provide an improved spinal fixation device.

SUMMARY OF THE INVENTION An object of the present invention is to provide a spinal fixation device that is easy to manufacture and assemble and that is easy to apply at the procedure site.

1 is a schematic exploded perspective view of an example of a spinal fixation device according to the prior art.

Figure 2 is a schematic cross-sectional view of another example of a spinal fixation device according to the prior art.

Figure 3 is a schematic exploded perspective view of the spinal fixing device according to the present invention.

Figure 4a is a partial cross-sectional view showing a state in which birds are coupled to the head of the pedicle screw of the spinal fixation device according to the present invention.

4B is a side view of FIG. 4A.

5A and 5B are front and side views showing contact of the rod shown with the locker and set screw assembled;

6 is a perspective view showing the bottom of the locker;

7A, 7B and 7C are front, side and top views of a spinal fixation device according to the present invention.

<Brief Description of Major Codes in Drawings>

31.Pedicle Screw 32.Head

33. Helix 34. Birds

36.Rod 37.Lockers

39.Set screw 41.Ring

In order to achieve the above object, according to the present invention, having a head formed on top and pedicle screw screwed to the vertebrae; Saddle is installed in the inner lower portion of the head to enable the circular motion within a predetermined range; A rod disposed above the saddle and connected to another pedicle screw; A rocker having a lower curved surface pressed against the rod to maintain the rod movably; A set screw coupled to the locker and coupled to a spiral formed on an inner surface of the head; And a ring coupled to the upper portion of the head.

According to one feature of the invention, the side of the saddle is formed with a groove extending in a curved form, the end of the pin inserted from the outer peripheral surface of the head is inserted into the groove to limit the movement of the birds.

According to another feature of the invention, a plurality of grooves are formed in the bottom of the rocker to increase the frictional force of the rocker against the rod.

According to another feature of the invention, a plurality of embossings are formed on the bottom of the rocker to increase the frictional force of the rocker against the rod.

According to another feature of the invention, the tool insertion groove is formed on the top of the set screw.

According to another feature of the invention, the saddle is formed in the saddle corresponding to the outer peripheral surface of the rod to accommodate the rod in the curved surface.

Hereinafter, with reference to an embodiment shown in the accompanying drawings the present invention will be described in more detail.

3 is a schematic perspective view of one embodiment of a spinal fixation device according to the present invention.

Referring to the drawings, the spinal fixation device according to the present invention is a pedicle screw 31 having a head 32 formed thereon, saddle 34 accommodated in the inner lower portion of the head 32, and the saddle 34 The inner surface of the head 32 as being caulked with the rod 36 disposed above the rod, the interface locker 37 disposed in point contact with the rod 36, and the rocker 37. It has a set screw 38 coupled to the spiral portion 33 formed in the, and a ring 41 coupled to the upper portion of the head (32).

The head 32 is formed of two branches 32a and 32b as shown in the figure. The spiral part 33 is formed in the inner surface of the branch part 32a, 32b. In addition, protrusions 32c extending in the circumferential direction are formed on the outer surfaces of the branching portions 32a and 32b, and the protrusions 32c prevent the detachment of the ring 41 as described later in more detail. It will play a role. Through holes 32d are formed in the branch portions 32a and 32b, respectively, and the pins 42 may be inserted through the holes 32d.

The saddle 34 has an upper surface formed of a curved portion 34a, as shown in the figure, and this curved portion 34a corresponds to the outer circumferential surface of the rod 36. The lower surface of the saddle 34 is also formed as a curved portion, which corresponds to the curved surface formed below the inner surface of the head 32. Pin insertion grooves 35 are formed at both sides of the saddle 34, and the pins 42 are inserted in an interference fit from the outside through the through-holes formed in the head 32, and the ends of the saddles 34 are closed. It is inserted into the pin insertion groove 35.

The saddle 34 is allowed for a range of motion inside the head 32. That is, the sliding movement along the inner surface of the head 32, the movement of the saddle 34 is limited by the pin 42 inserted into the pin insertion groove (35). The pin insertion groove 35 extends in a curve as shown in the figure. The movement of the saddle 34 will be described in more detail later.

The rod 36 may have a straight shape as shown in the figure, or may be deformed to have an appropriate curvature at the surgical site. The rod 36 is held in one position by being pressed by the lower surface of the rocker 37 in a state seated in the curved portion 34a formed on the upper surface of the saddle 34.

As shown in the drawing, the locker 37 has a caulking portion 38 formed at an upper portion, and a convex curved portion 37a is formed at an entire lower portion thereof. The curved portion 37a is in point contact with the curved surface formed on the outer circumferential surface of the rod 36. It will be appreciated that if the angle of inclination of the rod 36 with respect to the head 32 changes, the rod 36 will make a rolling motion on the curved portion 37a of the rocker 37.

The locker 37 is engaged via caulking against the set screw 39. A spiral portion is formed on the outer circumferential surface of the set screw 39, so that the set screw 39 can be engaged with the spiral portion 33 formed on the inner surface of the head 32. A tool insertion groove 40 is formed inside the set screw 39. In the example shown in the drawing, it can be seen that a hexagonal groove is formed. The tool can be inserted into the tool insertion groove 40 so that the set screw 39 can be pushed against the spiral portion 33 of the head 32.

The ring 41 is formed such that the upper end of the head 32 is inserted therein. That is, as shown in the figure, two parallel straight portions 41a and curved portions 41b connecting the straight portions 41a are provided. The inner circumferential surface curvature of the curved portion 41b corresponds to the outer circumferential surface curvature of the head 32. In practice, the ring 41 is coupled to the lower portion of the protrusion 32c described above, whereby the ring 41 can be prevented from being separated from the head 32 by the protrusion 32c.

4A is a partial cross-sectional view showing a state in which birds are coupled to the head, and FIG. 4B is a right side view of FIG. 4A.

Referring to FIG. 4A, it can be seen that the saddle 34 is restricted by the pin 42 and inserted through the aperture of the head 32 of the pin 42. 4B, it can be seen that the saddle 34 is curved in a predetermined range in the direction of the arrow A along the curved surface 32e formed inside the head 32. In practice, the movement of these saddles 34 results in allowing the rods 36 (FIG. 3) disposed thereon to tilt in the range of about 10 °.

5A and 5B are front and side views showing a state in which the locker and the set screw are engaged.

Referring to the drawings, the locker 37 is coupled to the lower portion of the set screw 39 through the cocking. The set screw 39 and the locker 37 are in fact provided mutually coupled to the surgical site. The lower surface of the locker 37 is pressed against the rod 36 through point contact, thereby serving to press-fix the rod 36 together with the saddle 34. The spiral portion formed on the outer surface of the set screw 39 is coupled to the spiral portion formed inside the head 32, and this coupling is used to insert a tool (not shown) into the tool insertion groove 40 formed inside the set screw 39. By inserting it in.

6 is a perspective view for showing the lower surface of the rocker.

Referring to the drawings, the lower surface of the locker 37 is preferably formed with a plurality of grooves 61, as shown in the figure. As the groove 61 is formed, the grounding force on the rod 36 may be improved. That is, the friction force can be increased by forming a plurality of grooves 61 between the lower surface of the rocker 37 and the surface of the rod 36 which make substantial point contact, whereby the traction force can be improved. In another example not shown in the figure, the embossing may be formed instead of the groove 61 to improve the traction force.

7A to 7C are front, side and plan views showing each of the components described with reference to FIGS. 3 to 6 in a coupled state above.

Referring to the figure, the rod 36 can make an inclined motion with respect to the head 32 within a predetermined angle range, as shown in phantom lines, such an angle range of up to 10 degrees. In addition, as described above, the rod 36 may be applied by bending at the surgical site depending on the region of the spine to which it is applied.

Hereinafter, the assembly procedure of the spinal fixing device according to the present invention will be described briefly.

A spinal fixation device is provided for implanting the spinal fixation device into the patient's body, in which the head 32 is assembled with the saddle 34 constrained by the pins 42, the set screw 39 and the locker. Reference numeral 37 is provided in the state of being mutually coupled by cocking. The operator first screws the pedicle screw 31 to the vertebrae of the patient. The rod 36 is then placed on top of the saddle 34 and the ring 41 is engaged. When the ring 41 is engaged, the ring 41 must travel downward through the protrusion 32c formed at the top of the head 32, so that the operator uses the ring coupling pusher to ring the ring 41. It can be easily recognized that the ring 41 is correctly coupled in place by the sense of the finger while engaging the.

Next, the assembly of the locker 37 and the set screw 39 is inserted through the ring 41 into the head 32, and the set screw 39 is inserted into the spiral portion 33 of the head 32. To combine. The coupling to the head 32 is achieved by inserting and rotating a tool (not shown) into the tool insertion groove 40. When the set screw 39 is rotated, the rocker 37 does not rotate because the cocking engagement allows the relative rotation of the set screw 39 and the rocker 37.

By the combination of the set screw 39, the locker 37 presses the upper portion of the rod 36, and at the same time, the branch portions 32a and 32b of the head 32 are slightly opened. Opening of these branches 32a and 32b results in the ring 41 not being able to escape upwards beyond the projection 32c.

Spinal fixing device according to the present invention has the following advantages.

First, the manufacturing and fixing of the fixing device is easy. The spinal fixation device, which is constituted by a reduced number of parts as compared to the conventional device, is not only easy to manufacture but also easily and accurately performed. For example, as described above, the practitioner can recognize whether the engagement of the ring 41 is correctly performed by the sense of the finger manipulating the ring pusher, and only by the engagement of the set screw 39 to the overall device. The completed combination of is made.

Secondly, it is possible to visually check the state of engagement of the overall device that proceeded after the ring 41 is coupled. This is because the ring 41 has been slimmed down, and the overall mechanism can achieve a stable bond even by the slimized ring 41.

Third, the fixing of the rod 36 by the rocker 37 and the saddle 34 is made very stable. In particular, the groove or embossing formed on the bottom of the rocker 37 prevents fine slip of the rod due to the movement of the patient. It plays a role.

Although the present invention has been described with reference to one embodiment shown in the accompanying drawings, this is merely exemplary, and those skilled in the art can make various modifications and other equivalent embodiments therefrom. You will understand. Therefore, the true scope of protection of the present invention should be defined only by the appended claims.

Claims (5)

A pedicle screw having a head formed thereon and screwed to the vertebra; Saddle is installed in the inner lower portion of the head to enable the circular motion within a predetermined range; A rod disposed above the saddle and connected to another pedicle screw; A rocker having a lower curved surface pressed against the rod to maintain the rod movably; A set screw coupled to the locker and coupled to a spiral formed on an inner surface of the head; And, And a ring coupled to the top of the head. The method of claim 1, The side of the saddle is formed with a groove extending in a curved shape, the end of the pin inserted from the outer peripheral surface of the head is inserted into the groove is limited by the movement of the saddle characterized in that the movement of the saddle. The method of claim 1, And a plurality of grooves are formed on the bottom of the rocker to increase the frictional force of the rocker against the rod. The method of claim 1, And a plurality of embossings are formed on the bottom of the rocker to increase the frictional force of the rocker against the rod. The method of claim 1, The saddle has a curved surface corresponding to the outer circumferential surface of the rod to accommodate the rod within the curved surface, characterized in that the saddle.