KR200249294Y1 - screw for fixing spine - Google Patents

Abstract

The present invention relates to a spine, in particular a pedicle fixation screw, and more particularly to a spinal fixation screw for fixing the spine by using a cap for fixing a rod disposed on an implant installed implanted in the spine It is about.

Description

Screw for fixing spine

The present invention relates to a spine, in particular a screw for fixing the pedicle, spinal fixation for fixing the spine in particular by using a cap for fixing the rod disposed on the implant (implant) installed implanted in the spine It is about a dragon screw.

An apparatus of this kind is disclosed in Utility Model Registration No. 175040 filed by the applicant, and is shown in FIGS. 1 and 2.

Figure 1 is a perspective view showing a spinal fixation screw applicant of the present applicant, Figure 2 is a cross-sectional view showing a combined state of FIG. As shown in FIGS. 1 and 2, the screw for fixing the spine 1 has vertical extensions 7 on both sides of the rod receiving portion 5 for receiving the rod 3, and the rod receiving portion 5. A female threaded portion 11 for transferring the male threaded body 9 for fixing the rod 3 housed therein by screwing is formed in the vertical extension portion 7 and through the connecting member 13 of the male threaded body 9. The rim portion 15 is configured to surround the outside of the vertical extension portion 7 with the transfer.

In the above-described configuration, the connecting member 13 connects between the lower end of the rim portion 15 and the recess portion 17 formed at the lower portion of the male screw body 9. Unexplained reference number 2 is a screw and 10 is a wrench groove.

From this configuration, the screw for fixing the spine 1 has the following problems.

First, it is very difficult to make the central axis of the male screw body 9 coincide with the central axis of the vertical extension part 7 because the contact between the threads is made first when the male screw body 9 is initially fastened to the female screw part 11. This can lead to a delay in the operation time.

Second, since the recessed portion 17 is formed near the lower portion of the male screw body 9, the number of threads of the male screw body 9 can be reduced, thereby lowering the fastening force.

Third, since the connecting member 13 is formed at the lower end of the rim portion 15, when the rod 3 is curved, the connecting member 13 contacts the rod 3 first, so that the male screw 9 is loaded with the rod 3. The contact force of the rod 3 can be lowered because it is not sufficiently in contact with the.

Fourth, the bottom surface of the male screw body (9) is formed in a plane, when the rod 3 seated on the rod receiving portion (5) is curved or inclined, the contact area is small to reduce the fixing force of the rod (3) have.

Fifth, the seating surface 6 of the rod receiving portion 5 is formed horizontally, when the rod 3 is disposed to be inclined with respect to the seating surface 6 is not tightly fixed to the rod receiving portion 5 rod ( The fixing force of 3) can be reduced.

Sixth, the rim portion 15 is no longer transported downward at the locking jaw position formed on the outer circumferential surface of the vertical extension portion 7. At this time, in the case of surgery that requires a stronger fixing of the rod, a very strong fastening force should be applied to the male screw (9). However, the flesh thickness of the rim portion 15 is uniformly formed, and as the male screw body 9 is fastened, excessive force is applied to the rim portion 15 so that it may be crushed in an elliptical shape or ruptured radially. As a result, the rim portion 15 does not surround the outer circumferential surface of the vertical extension portion 7, so that the fixing of the rod may be uncertain.

The present invention was devised to solve the above-mentioned problems, and in fixing the rod accommodated in the implant, the spine is provided with a structure that can not only easily match the central axis of the male thread and the central axis of the female thread but also secure the rod. To provide the fixing screws.

Figure 1 is a perspective view showing a screw for spinal fixation filed by the applicant.

2 is a cross-sectional view showing a combined state of FIG.

Figure 3 is a perspective view showing a screw for spinal fixation according to an embodiment of the present invention.

4 is a cross-sectional view taken in the radial direction of the rod in the initial bonded state of FIG.

5 is a cross-sectional view of the combined state of Figure 4 is completed.

6 is a cross-sectional view taken in the longitudinal direction of the rod in the coupled state of FIG.

7 is a plan view of the cap;

8 is a perspective view showing a state of use of the device of the present invention.

<Explanation of symbols for the main parts of the drawings>

100: screw for fixing the spine 110: implant

150: cap 120: screw

130: head portion 130a, 130b: vertical extension portion

131: rod receiving portion 133: seating surface

135a, 135b: Female thread 137a, 137b: Insertion guide

139: Jam Jaw 140: Rod

150: cap 151: male thread

151a: Wrench groove 151b: Bottom surface of male thread

152: recess 153: rim

153a, 153b: groove portion 154a, 154b: flat portion

155a, 155b: connecting member 156a, 156b: gap

170: pedicle

The present invention for achieving the above object is an implant having a screw inserted into the bone, a pair of vertical extension formed with a rod receiving portion and a female screw portion for receiving the rod; In the screw for fixing the spine comprising a cap coupled to the implant,

The cap is a male screw body for fixing the rod through the screw connection with the female screw portion; A rim portion surrounding the outer side of the vertical extension portion; One side protrudes from an upper end of the rim portion so that the male threaded body is rotatably supported with respect to the rim portion, and the other side includes a pair of connecting members accommodated in a recess formed in the male threaded body. Can increase the number,

An insertion guide portion is further formed at the upper end of the vertical extension portion to be inserted between the rim portion and the male threaded body so as to coincide with the central axis of the male threaded body and the central axis of the vertically extended portion.

In the above-described configuration, the inner circumferential surface of the rim portion can be prevented from turning to the rim portion by the configuration in which flat portions facing each other are formed in parallel.

Each of the connecting members protrudes from an upper end of the rim having the flat portion, and the height of the vertical extension portion is higher than that of the rim, so that the protrusion of the insertion guide portion is secured in the fixed state of the rod. Can be induced.

Further, the concave portion is formed at the lower end of the rim portion in which the flat portions are formed, whereby contact between the lower end surface of the male screw body and the rod can be more reliably maintained.

In addition, the bottom surface of the male screw body in contact with the rod is formed in an arc shape, it is possible to increase the contact area with the rod accommodated inclined.

On the other hand, by forming the rod receiving portion to be inclined, the implant is installed where the pedicle is inclined can increase the adhesion to the rod even if there is a difference in height.

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

Figure 3 is a perspective view showing a screw for spinal fixation according to a preferred embodiment of the present invention, Figure 4 is a cross-sectional view taken in the radial direction of the rod in the initial coupled state of Figure 3, Figure 5 is a combination of Figure 4 State is a cross-sectional view, Figure 6 is a cross-sectional view cut in the longitudinal direction of the rod in the combined state of Figure 3, Figure 7 is a plan view showing a cap, Figure 8 is a perspective view showing a state of use of the device of the present invention to be.

As shown in Figure 3 to 8, the screw for fixing the spine 100 according to a preferred embodiment of the present invention is largely composed of an implant 110 and a cap 150.

In the above-described configuration, the implant 110 is composed of a screw 120 and the head portion 130 that is embedded in the spine or pedicle 170.

The head part 130 includes a pair of vertical extension parts 130a and 130b in which a U-shaped groove is formed. A rod accommodating part 131 is formed between the vertical extension parts 130a and 130b to accommodate the rod 140. If the pedicle to be implanted is curved (usually, the spine or sacrum is curved), there may be a difference in the height of the plurality of implants 110 implanted in the pedicle. Thus, the rod 140 is inclined and the adhesion between the rod 140 and the rod accommodating portion 131 is lowered, so that the rod 140 cannot be securely fixed. In order to solve this, it can be overcome by forming the seating surface 133 of the rod receiving portion 131 to be inclined. This inclination angle is preferably set to 5 ° to 20 °, preferably 10 °.

In addition, female threads 135a and 135b are formed on the inner circumferential surfaces of the vertical extension parts 130a and 130b to accommodate the male thread body 151 described below for fixing the rod 140 seated on the rod receiving part 131. have. In addition, the insertion guide portions 137a and 137b for aligning the central axis of the male screw body 151 with the central axes of the female thread portions 135a and 135b are vertical extension portions 130a and 130b, and more specifically, the female thread portion 135a. , 135b) is formed successively. That is, as shown in FIGS. 3 and 4, the insertion guide portions 137a and 137b in which the female thread portions 135a and 135b are not formed are formed by the threads of the male screw body 151 and the female thread portions 135a and 135b. It is inserted between the rim 153 and the male threaded body 151 of the cap 150 described below until the thread first contacts. Accordingly, the outer side of the insertion guides 137a and 137b is surrounded by a part of the rim 135, and the inner side of the insertion guides 137a and 137b accommodates the male screw body 151. By this initial fastening structure, as shown in FIG. 4, the male screw body 151 and the rim portion 153 are installed in a form supported by the insertion guide portions 137a and 137b of the vertical extension portions 130a and 130b. Therefore, the operator can easily install the cap 150 on the implant 110, as well as to match the center axis of the male thread 151 and the center of the female threaded portions (135a, 135b). In this state, the operator can simply fasten the cap 150 to the implant 110 without misalignment by simply rotating the male screw body 151. Therefore, the surgical operation can be performed quickly and accurately.

In particular, the rim portion 153 is supported by the insertion guide portions 137a and 137b to match the center axis of the male screw body 151 with the center of the vertical extension portions 130a and 130b. Thus, the height of the rim 153 (ie, the portion surrounding the vertical extension) is substantially higher than the lead (length of the thread) of the male screw 151 (that is, the lower end surface of the rim is lower than the lower surface of the male screw body). More protruding structure).

In addition, each of the insertion guides 137a and 137b may protrude through the gaps 156a and 156b between the rim 153 and the male screw 151 while the male screw 151 fixes the rod 140. It is configured to. Therefore, even if the insertion guides 137a and 137b are formed, it is not necessary to reduce the number of threads of the male screw body 151, so that the predetermined fastening force can be maintained as it is. This guides the insertion guide portions 137a and 137b of the vertical extension portions 130a and 130b to easily protrude from the upper end of the rim portion 153 by the flat portions 154a and 154b described later, thereby extending the vertical extension portions 130a and 130b. In more detail, the combined height of the female screw parts 135a and 135b and the insertion guide parts 137a and 137b may be higher than the height of the rim 153.

A locking jaw 139 is formed on the outer circumferential surfaces of the vertical extension portions 130a and 130b to prevent the lower end of the rim portion 153 from being further moved downward. If the diameter of the rod 140 is small and there is no catching jaw 139, if the male screw body 151 passes near the boundary, the number of threads of the thread may decrease, thereby weakening the tightening force. In order to prevent the weakening of the fastening force, the locking jaw 139 is installed near the boundary between the rod receiving part 131 and the female screw parts 135a and 135b. Of course, it will be apparent that the female threads 135a and 137b may be formed to extend to the inner surface of the rod receiving portion 131 instead of installing the locking step 139.

Cap 150 for fixing the rod 140 is largely composed of a male screw body 151, a rim portion 153, connecting members (155a, 155b).

The male screw body 151 is conveyed through the screw coupling with the female screw parts (135a, 135b) serves to fix the rod (140). A wrench groove 151a for easily turning the male threaded body 151 is formed at an upper portion of the male threaded body 151. The bottom surface 151b of the male threaded body 151 touching the rod 140 may be formed in a flat or convex arc shape. In particular, in the case of an arc shape, the contact area is supported even when the rod 140 is bent and inclined. The fixing force can be increased by increasing.

As described above, the rim portion 153 stably maintains the central axis of the male screw body 153 at the initial stage of fastening, and after the fastening, the outer side of the vertical extensions 130a and 130b to prevent the vertical extension portions 130a and 130b from opening. Take the structure that surrounds it. Accordingly, the vertical extension portions 130a and 130b are provided between the inner side of the rim portion 153 and the threads of the male screw body 151, that is, the gaps 156a and 156b. In addition, a pair of grooves 153a and 153b are formed at the lower end of the rim portion 153 to face each other. The shape of the grooves 153a and 153b may be determined according to the cross-sectional shape of the rod 140. However, since the cross-section of the rod is generally circular, it is preferable that the grooves 153a and 153b be formed in a semicircle. However, the grooves 153a and 153b may be installed at the same position as the U-shaped groove of the rod receiving unit 131 to accommodate the rod 140. To this end, the rim 153 is formed with flat portions 154a and 154b. That is, the flat portions 154a and 154b are formed by changing the thickness of the rim portion 153. For example, as shown in FIG. 7, the flesh of the rim portion 153 at the position where the recesses 153a and 153b are installed is provided. The thickness can be achieved by making the thickness thicker than the flesh thickness of the rim portion 153 (part where the gaps 156a and 156b are formed). As a result, the gap size between the flat portions 154a and 154b and the male screw 151 is smaller than the thickness of the vertical extensions 130a and 130b, so that the vertical extensions 130a and 130b are always the gaps 156a and 156b. Induce it to intervene. Therefore, even if the male screw body 151 is rotated, the rim portion 153 is not rotated by the interaction between the flat portions 154a and 154b and the vertical extension portions 130a and 130b, so that the recess portions 153a and 153b are formed in the rod receiving portion. It can be located exactly in the U-shaped groove of (131).

As such, the cap 150 is inserted into and supported by the vertical extension portions 130a and 130b to a predetermined depth when initially installed in the implant 110, and by the flat portions 154a and 154b that prevent the rotation of the rim portion 153. Even if the operator rotates only the male screw 151 without holding the rim 153, the positions of the recesses 153a and 153b can be automatically positioned in the U-shaped grooves of the rod housing 131. Therefore, the operation of the operation can be convenient to perform the operation smoothly.

In addition, as described above, the thicknesses of the flat portions 154a and 154b are thicker than the thickness of other positions, so that they are relatively superior in strength to the thin portions. Therefore, in order to more secure the rod 140, even if the male screw 151 presses the rod 140 strongly, it is possible to prevent the crush or tear of the rim 153. Therefore, since the rim 153 stably surrounds the outer circumferential surfaces of the vertical extension parts 130a and 130b, the rod 140 can be securely fixed.

The connecting members 155a and 155b are elements for configuring the rim portion 153 and the male screw body 151 into a single body formed coaxially, and are composed of a pair of arms 155a and 155b. That is, one side of each of the arms 155a and 155b is formed to protrude horizontally from the upper end of the rim portion 153, and the other side is accommodated in the annular recess 152 formed in the cylindrical upper portion of the male screw body 151. The recess 152 allows the male threaded body 151 to rotate relative to the rim 153, and the rim 153 as the male threaded body 151 is transferred to the female threaded parts 135a and 135b. ) Is also conveyed and wrapped along the outside of the vertical extension (130a, 130b). In this way, the recess 152 is formed on the upper portion, so that the entire thread of the male screw body 151 can be fastened to at least the female screw portions 135a and 135b. The connecting members 155a and 155b are also provided at positions opposing the respective recesses 153a and 153b. This is to guide the vertical extension portions 130a and 130b, particularly the insertion guide portions 137a and 137b, between the gaps 156a and 156b by the flat portions 154a and 154b so as to protrude from the upper end of the rim portion 153. .

Screw for fixing the spine of the present invention is not limited to the above-described embodiment can be carried out by various modifications within the range allowed by the technical idea of the present invention.

As described above, according to the screw for fixing the spine of the present invention has the following effects.

First, the insertion guide portion for receiving and supporting the male screw body on the inner side and the rim portion wrapped and supported on the outer side before forming the female screw portion is formed in the vertical extension portion, the operator simply installs the cap on the implant and at the same time the central axis of the male screw body And the center of the vertical extension can be matched. As a result, fast and accurate fastening can be made and the operation time can be shortened.

Second, the connection member connecting the rim portion and the recessed portion of the male threaded body is formed at the top, thereby increasing the number of threads of the male threaded body to increase the tightening force.

Third, a thick flesh flat portion is formed on the inner circumferential surface of the rim in parallel to each other, preventing rotation of the rim with respect to the rotation of the male screw, thereby smoothly conveying the male screw, thereby shortening the fastening time. In addition, even if the male screw exerts strong pressure on the rod, the rim may be crushed or prevented from being ruptured. Thus, the rod can be fixed securely.

Fourth, each of the connecting members protrudes from the upper end of the rim having the flat portion, so that the position of the insertion guide portion can be reliably guided.

Fifth, the height of the vertical extension portion is formed higher than the height of the rim portion, it is possible to maintain the number of threads of the female thread portion in spite of the formation of the insertion guide portion.

Sixth, a groove is formed at a lower end of each of the rims on which the flat portion is formed, so that the groove is not only located in the groove of the rod receiving portion, but the curved portion is accommodated in the groove receiving portion and the male screw and the rod are formed. The contact area of the liver can be increased. Therefore, the male screw body can securely fix the rod.

Seventh, the bottom surface of the male screw body is formed in a convex arc shape, it is possible to increase the contact area between the curved rod or inclined rod and the male screw body.

Eighth, since the seating surface of the rod housing is inclined, the rod housing may be fixed to the rod housing even if the rod is inclined.

Claims (6)

An implant having a screw inserted into the spine and a pair of vertical extension portions formed with a rod receiving portion and a female screw portion for receiving a rod; In the screw for fixing the spine comprising a cap coupled to the implant, The cap is a male screw body for fixing the rod through the screw connection with the female screw portion; A rim portion surrounding the outer side of the vertical extension portion; One side is formed to protrude from the upper end of the rim portion so that the male screw body is rotatably supported relative to the rim portion, and the other side is composed of a pair of connecting members accommodated in the recess formed in the male screw body, The upper end of the vertical extension portion is inserted between the rim and the male screw body, the screw for fixing the spine, characterized in that the insertion guide portion is further formed to match the central axis of the male thread and the vertical extension portion. The screw for fixing a spine of claim 1, wherein the inner circumferential surface of the rim portion has flat portions facing each other in parallel. According to claim 2, wherein each of the connecting member is formed protruding on the upper end of the rim formed with the flat portion, Spinal fixing screw, characterized in that the height of the vertical extension is formed higher than the height of the rim. The screw for fixing a spine of claim 2 or 3, wherein a recess is formed at a lower end of each of the rims having the flat portions formed therein. The screw of claim 1, wherein the lower end surface of the male screw body in contact with the rod has an arc shape. The screw for fixing a spine of claim 1, wherein the rod receiving portion is inclined.