CN202128539U - Special device for taking out perfusion cervical pedicle screw - Google Patents

Abstract

The utility model relates to a remover in surgical instruments, in particular to a remover specially used for removing perfusion pedicle screws, the remover is an outer rod with an outer hexagonal screwdriver head (1-1) at one end (1), it is characterized in that an inner rod (2) is coaxially pierced in the body of the outer rod (1), and one end of the non-external hexagonal screwdriver head of the outer rod (1) is evenly provided with several slits ( 8), a self-centering clamping device is set at the cutout (8) to clamp the outer rod (1) and the inner rod (2); the inner rod (2) is located on the outer rod One end of the outer hexagonal screwdriver head (1-1) of (1) is a straight screwdriver head (2-1). The nail remover of the utility model has the advantage that the thread is not easy to slip.

Description

A screw remover specially used for removing perfusion pedicle screws

technical field

The utility model relates to a remover in surgical instruments, in particular to a remover for bone fixation screws.

Background technique

In the treatment of cervical spine injuries, the anterior vertebral screw-plate system is commonly used at home and abroad at present. This system fixes the steel plate on the damaged vertebral body through screws, which can maintain the strength of cervical spine fixation and keep the fixed segment real-time. Stablize. However, if the vertebral soft tissue is infected or the steel plate is broken or loosened, it is necessary to withdraw the screw therein from the vertebra, and then take out the steel plate. The screws are usually hexagon socket head screws. During the screw removal process, if the holding force between the screw and the vertebra is too large or the hexagon head of the nail remover used does not match the hexagon socket hole of the screw, it is easy to The phenomenon of thread slipping occurs, which makes the screw unable to be removed; especially when the bone cement is perfused around the screw body, there is a great holding force between the screw and the vertebrae, and it is difficult to remove the screw with a common hex head screw remover. unscrew. For example, one of the inventor's authorized new patents (authorized announcement number is CN 201591614U) discloses "a kind of perfusion anterior cervical pedicle screw". The bottom of the screw head is provided with a columnar counterbore extending toward the nail head, and a perfusion core for perfusing bone cement is provided in the counterbore, and the perfusion core is a slotted stud. Threaded connection; when the pedicle screw is in use, bone cement is poured around the screw body, and the holding force between the screw body and the vertebra is very large. Therefore, it is necessary to design a nail remover specially designed for taking out the pedicle screw.

Contents of the invention

The technical problem to be solved by the utility model is to provide a nail remover, which is specially used for removing perfusion pedicle screws.

The technical solution adopted by the utility model to solve the technical problem is:

A nail remover specially used for taking out perfusion pedicle screws, the nail remover is an outer rod with an outer hexagonal driver head at one end, it is characterized in that an inner rod is coaxially pierced inside the outer rod , and one end of the non-external hexagonal screwdriver head of the outer rod is evenly provided with several cutouts, and a centering clamping device is arranged at the cutout to clamp the outer rod and the inner rod together; the inner rod is located at the One end of the outer hexagonal screwdriver head of the outer rod is a straight screwdriver head.

The utility model relates to a nail remover specially used for taking out perfusion pedicle screws, wherein the self-centering clamping device can be a known three-jaw chuck, and its structure can be clamped with a pistol drill The three-jaw chuck that holds the drill bit is the same, and it can also be similar to the structure of the three-jaw chuck on a common lathe. A simple alternative to the above scheme of clamping the outer rod and the inner rod together is that the surface of the outer rod at the cutout is provided with a tapered external thread, and the self-centering clamping device is compatible with the Nuts that match the tapered external threads described above.

The utility model relates to a nail remover specially used for taking out perfusion pedicle screws, wherein a screw connection structure is provided between the inner rod and the outer rod. The advantage of using threaded connection between the inner rod and the outer rod is that after the relative position between the inner rod and the outer rod is adjusted, the relative position between the two will not be easily changed before being clamped by the self-centering clamping device .

The utility model relates to a nail remover specially used for taking out perfusion pedicle screws, wherein the outer rod is made of memory alloy. The advantage of using memory alloy is that the outer rod is placed in a low-temperature environment before taking out the screw to reduce its volume. Under the environment of human body temperature, the volume expands, so that the outer hexagonal screwdriver head of the outer rod is tightened in the inner hexagonal counterbore of the pedicle screw, reducing the possibility of slippage.

The special nail remover described in the utility model, wherein the outer hexagonal screwdriver head end of the outer rod and the authorized utility model patent "a kind of perfusion anterior cervical pedicle screw" (authorized announcement number is CN 201591614U) The inner hexagonal counterbore of the pedicle screw in the inner rod matches, and the flat-shaped screwdriver head end in the inner rod matches the flat-shaped groove of the perfusion core at the bottom of the inner hexagonal counterbore in the said pedicle screw; therefore , as long as the rotation direction of the thread on the pedicle screw and the perfusion core is set to be reversed, and the relative positional relationship between the outer rod and the inner rod is adjusted so that the outer hexagonal screwdriver head of the outer rod and the inner rod have a The glyph-shaped screwdriver head matches the inner hexagonal hole in the pedicle screw and the inline groove of the perfusion core respectively. When the screw is taken out, the outer rod and inner rod can apply force to the pedicle screw at the same time, which is different from the existing one. Compared with the ordinary hexagon head screw remover, the unscrewing force that the pedicle screw can withstand is significantly increased, which reduces the possibility of slippage.

Description of drawings

1 to 5 are schematic structural views of a specific embodiment of the nail remover described in the present invention, wherein 1 is a front view, FIG. 2 is a top view, FIG. 3 is a bottom view, and FIG. 4 is a sectional view of A-A of FIG. 1 Enlarged view, Fig. 5 is a partial enlarged view of the three-jaw chuck in Fig. 1 .

6 to 8 are schematic structural views of another embodiment of the nail remover according to the present invention, wherein 6 is a front view, FIG. 7 is a bottom view, and FIG. 8 is a B-B sectional view of FIG. 6 .

9 to 11 are schematic structural views of the third specific embodiment of the nail remover described in the present invention, wherein 9 is a front view, FIG. 10 is a C-C sectional view of FIG. 9 , and FIG. 11 is a D-D sectional view of FIG. 9 .

Detailed ways

Example 1

Referring to Figures 1 to 5, the outer rod 1 in this embodiment is made of memory alloy, its lower end is an outer hexagonal screwdriver head 1-1, and its upper end is a jacket 1-2 with three circumferentially evenly distributed slits 8 ; The center of the outer rod 1 is provided with an axial through hole, which is pierced with an inner rod 2, and the lower end of the inner rod 2 is a straight screwdriver head 2-1 (see Fig. 1 and Fig. 2). Referring to Figures 3 to 5, the jacket 1-2 is provided with a self-centering clamping device for clamping the jacket 1-2 and the inner rod 2 together, and the self-centering clamping device is set on the jacket The three-jaw chuck outside 1-2, the three-jaw chuck is composed of a chassis 3-1 and an upper cover 3-2, wherein the center of the chassis 3-1 is provided with a through hole matching the outside of the sleeve, and the center of the chassis 3-1 The upper end is provided with an annular groove around the center, and the bottom of the annular groove is evenly distributed with three slide grooves in the circumferential direction. One end of the slide groove is flush with the outer wall of the annular groove, and the other end is connected to the bottom of the chassis 3-1. On the through hole, the wall of the through hole of the chassis 3-1 above the chute is provided with a gap extending from the upper end surface of the chassis 3-1 to the chute; each of the chute is provided with a The sliding block 5 loaded on the gap, the upper end surface of the sliding block 5 is provided with end thread; the annular groove is embedded with an end gear 6, and the lower end surface of the end gear 6 is provided with the above-mentioned sliding The end face thread of the block 5 is matched with the end face thread, and gear teeth are arranged on the upper end face; a driving gear 7 meshing with the above-mentioned end face gear 6 is provided on the outer wall of the annular groove, and one end of the driving gear 7 is provided with an inner hexagonal hole . The upper cover 3-2 is embedded in the upper end of the chassis 3-1 and connected together by screws 9; the upper end of the upper cover 3-2 is integrated with the handle 3.

In the above-mentioned three-jaw chuck, the driving gear 7 is screwed through the inner hexagonal hole in the driving gear 7 to drive the end gear 6 to rotate, and then the end surface threaded connection between the end gear 6 and the slider 5 makes the slider 5 work. Radial sliding, thereby clamping or loosening the jacket 1-2 on the upper end of the outer rod 1, because the jacket 1-2 is provided with a gap, so under the clamping action of the slider 5, the jacket 1-2 It will be hugged tightly on the inner rod 2, so that the outer rod 1 and the inner rod 2 are fixedly connected together.

Example 2

Referring to Figures 6 to 8, the difference between this embodiment and Embodiment 1 is that: the outer rod 1 and the inner rod 2 are connected by threads; the jacket 1-2 at the upper end of the outer rod 1 is provided with four There are notches 8 evenly distributed in the circumferential direction, and a tapered external thread is provided on the outer wall of the jacket 1-2. The self-centering tightening device is a nut 4 matching the tapered external thread. The upper end of the nut 4 is connected to the handle 3 made into one.

Example 3

Referring to Figures 9 to 11, the difference between this embodiment and Embodiment 1 is that five circumferentially uniform cutouts 8 are provided on the jacket 1-2 at the upper end of the outer rod 1; the outer wall of the jacket 1-2 is provided with There is a tapered external thread, and the self-centering tightening device is a nut 4 matching the tapered external thread; the upper part of the outer rod 1 is provided with an external hexagonal head-shaped connecting part, and the lower end of the handle 3 is provided with a The hex head type connection part matches the internal hexagon hole.

Claims (5)

1. but nail-fetching device that is exclusively used in the taking-up perfusion cervical pedicle bolt; This nail-fetching device is for having the outer bar (1) that an end is an outer-hexagonal shape screwdriver head (1-1); It is characterized in that; Coaxially in described outer bar (1) body be equipped with bar (2) in, and an end of the non-outer-hexagonal shape screwdriver head of outer bar (1) evenly is laid with several otch (8), a self-centering clamping device is located at described otch (8) and locates outer bar (1) and interior bar (2) are clamped together; The end that described interior bar (2) is positioned at the outer-hexagonal shape screwdriver head (1-1) of said outer bar (1) is in-line screwdriver head (2-1).

2. but a kind of nail-fetching device that is exclusively used in the taking-up perfusion cervical pedicle bolt according to claim 1 is characterized in that described self-centering clamping device is a three-jaw chuck.

3. but a kind of nail-fetching device that is exclusively used in the taking-up perfusion cervical pedicle bolt according to claim 1; It is characterized in that; The surface of the outer bar (1) that described otch (8) is located is provided with conical external screw thread, and described self-centering clamping device is the nut (4) that is complementary with said conical external screw thread.

4. but according to claim 1,2 or 3 described a kind of nail-fetching devices that are exclusively used in the taking-up perfusion cervical pedicle bolt, it is characterized in that, be provided with screw connection structure between described interior bar (2) and the outer bar (1).

5. but a kind of nail-fetching device that is exclusively used in the taking-up perfusion cervical pedicle bolt according to claim 4 is characterized in that described outer bar (1) is processed by memorial alloy.

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