JPH1043199A - Tap for orthopedics - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the damage of soft tissue during tap raising work by helically providing plural blade parts at the top end of an axial body and continuously forming the rake faces and escape faces of respective adjacent blade parts. SOLUTION: At the axial center section of an axial body 11 of a tap for plastic surgery, a through guide hole 15 is formed and on the side face of a grip, a marker to become a mark for counting the number of rotations of the tap for orthopedics at the time of tap raising work is engraved. A screw part 12 is formed by helically continuing almost square plate bodies, and respective plural blade parts 14 forming the screw part 12 are formed from almost square corner parts. Then, the blade part 14 is composed of a rake face 14a, escape face 14b and cut blade 14c and rake faces 14a and escape faces 14b' of respective adjacent blade parts 14 are continuously formed. Thus, any longitudinal groove is not formed at the screw part, and a helical groove to be formed at the screw part is continuously formed without being interrupted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tap for forming an internal thread in a bone in orthopedic surgery.

[0002]

2. Description of the Related Art In orthopedic surgery, there is an operation in which an internal thread must be formed in a bone body. For example, when reconstructing a tendon or ligament, it may be necessary to first form an internal thread in the bone to fix the artificial or harvested tendon or ligament to the bone. The formation of an internal thread in such a bone body is performed by first forming a hole in the bone body, and then forming an internal thread in the formed hole with an orthopedic tap.

FIG. 5 shows a conventional example of this tap for orthopedic surgery, and FIG. 6 shows a tip portion of the tap. FIG. 6A is an enlarged view of a tip portion of the tap, and FIG. 6B is a cross-sectional view taken along the line AA in FIG. As shown in each of the drawings, a conventional orthopedic tap has a screw body 1 having a shaft 101 and blades 104, 104,...
02, a handle 103 provided at the base of the shaft body 101. Blade portions 104, 1 formed on the screw portion 102
.. Are spirally intermittently provided, and each blade portion 104 is composed of a rake face 104a, a flank face 104b, and a cutting edge 104c which is a crossing portion of these. .. Are arranged at appropriate intervals to form vertical grooves 105. Like the tap for metal working, the vertical groove 105 plays a role in releasing chips generated when cutting the screw groove of the female screw so as not to collect in the formed screw groove.

[0004]

However, in the orthopedic tap having such a configuration, the shape from the cutting edge to the rake face becomes a key shape, and there are many soft tissues such as a joint peripheral region, a spine, a cervical vertebra, and a lumbar vertebra. When used in parts, cutting edges or rake faces of ligaments, tendons, muscles, etc. were entangled or cut. In particular, such inconvenience is likely to occur in the case of a small operation under a mirror or an operation in a deep part.

[0005] By the way, the bone body is a brittle material, and the chips generated when forming the internal thread are powdery. Further, the bone body contains bodily fluid, and the holes forming the internal thread have other holes. Since the bodily fluid also flows from the body tissue, the generated chips are mixed with these bodily fluids to form a semi-fluid or very brittle mass of powder, and easily from between the blade and the formed screw groove It is considered that there is no need to form a vertical groove for allowing chips to escape like a tap for metal working.

Accordingly, an object of the present application is to provide an orthopedic surgical tap which does not damage soft tissue during tapping work, focusing on the material properties of a bone body.

[0007]

In order to solve the above-mentioned problems, an orthopedic tap according to the present invention has a plurality of blades spirally provided at the tip of a shaft body, and has a rake face and a clearance between adjacent blades. The surface is formed continuously. Here, the term “continuously formed” means that the rake face and the flank face of each adjacent blade portion are formed in a state of being smoothly connected without having a sharp curvature portion.

In the above-mentioned orthopedic tap, it is desirable that the height of the spirally provided blade portion is reduced toward the tip of the shaft body, that is, the outer diameter of the thread portion of the tap is reduced toward the tip. It is effective to provide the above-mentioned orthopedic tap with a hole penetrating the axis of the shaft.

Further, it is preferable that a handle is provided at the base of the shaft of the orthopedic tap, and a marker for measuring the number of rotations is provided on a part of the outer peripheral surface of the handle or the shaft. It is effective to make the handle provided at the base of the shaft into a rod shape and make the cross-sectional shape thereof horizontally long.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an orthopedic tap 1 according to the present invention. FIG. 1A shows an orthopedic tap 1.
1 (b) is a side view of the orthopedic tap 1. FIG. As shown in the figure, the orthopedic tap 1 has a shaft 11,
A plurality of blades 14, 14, located at the tip of the shaft 11
, Which are formed by spirally forming...
Is formed by a handle 13 provided at the base of the above.

A guide hole 15 is formed in the shaft center of the shaft body 11, and a mark is provided on the side surface of the handle 13 for counting the number of rotations of the orthopedic tap 1 during the tapping operation. Marker 16 is engraved. The marker 16 may be provided not on the handle 13 but on the outer peripheral surface near the base of the shaft 11. Further, a scale 17 for knowing the depth of the tap is provided near the screw portion 12 of the shaft body 11. The position of the scale 17 is determined in accordance with the length of the male screw usually used for the nominal diameter of the female screw to be formed,
The depth can be determined as a numerical value in increments of 5 mm or the like.

The shape of the handle 13 is as shown in FIG.
It is a rod-like body, is roughly a gourd in front view, and has a recess 13a formed so that a finger can be caught when grasped. With this shape, the user can grip the handle 13 firmly. The shape of the cross section of the handle 13 is horizontally long, and when the handle 13 is gripped and turned, a force can be applied to a position distant from the rotation axis, and a strong torque can be applied to the screw portion 12.

The shaft 11 of the tap 1 for orthopedic surgery
Although stainless steel is used as the material of the screw portion 12, any material may be used as long as it does not hinder the processing of the bone body. In addition, it is preferable to use a material that can repeatedly withstand the temperature and pressure due to autoclave sterilization. The thread portion 12 can be manufactured by grinding, cutting, rolling, or the like, and various sizes can be adopted.

FIG. 2 is an enlarged view of the screw portion 12. As shown in FIG. FIG.
2A is a front view of the screw portion 12, and FIG.
FIG. As shown in FIG. 2 (b), the screw portion 12 has a shape in which a substantially square plate is spirally connected, and a plurality of blade portions 14, 1 forming the screw portion 12 are formed.
Each of 4,... Is formed by a substantially square corner as shown in FIG. Each of the blades 14 is composed of a rake face 14a, a flank 14b, and a cutting edge 14c. The rake face and the flank of the adjacent blades 14 (for example, the rake face 14a and the flank of FIG. 2B). 14
b ') is formed continuously. Note that the screw portion 12 rotates in the S direction in the drawing when the tap is made. In this way, the thread 12 is not formed with a vertical groove as in a conventional orthopedic tap. At the same time, the helical groove formed in the screw portion 12 by such a configuration is formed continuously without interruption as in a conventional orthopedic tap.

In this case, the screw portion 12 is shown in FIG.
3 shows a shape in which substantially square plate bodies are spirally connected, but the shape of the screw portion 12 is not limited to this, and is shown, for example, in FIGS. 3 (a) to 3 (c). As described above, a shape in which polygonal plate bodies such as a triangle and a hexagon are spirally connected, or a shape in which corners are provided at positions intersecting the major axis of an ellipse in a spiral shape may be used. . That is, the screw portion 1
2 has a blade portion 14 for cutting a thread groove portion of a female screw to be formed, and a rake face 14a of an adjacent blade portion 14
By forming the flank 14b and the flank 14b continuously, any shape can be adopted as long as there is no longer any longitudinal groove formed between the blades 14.

The screw portion 12 is a spirally provided blade portion 1.
Are configured so that the height of 4, 14, ... decreases toward the tip of the shaft body 11, that is, the outer diameter of the screw portion 12 decreases toward the tip. The line connecting the tips of the blades 14, 14, ... has a spindle shape. The lines connecting the tips of the blades 14, 14,... May have a triangular shape. With such a configuration, as the screw portion 12 advances forward, the thread is gradually cut from a shallow thread groove to a deep thread groove, and a desired female screw can be formed smoothly at one time.

Next, the manner of use of the orthopedic tap 1 having the above configuration will be described below with reference to FIG. FIG.
FIG. 4 is a diagram showing a state where the orthopedic tap 1 forms an internal thread in the bone body X. First, a pilot hole h having a diameter slightly larger than the outer diameter of the shaft body 11 is drilled at a position where a female screw of a bone body is to be formed. Next, a guide wire w for guiding the orthopedic tap 1 to the prepared hole h.
Pass through. Then, the rear end of the guide wire w is inserted into the guide hole 15 from the front end of the shaft 11 of the orthopedic tap 1. In this state, the orthopedic tap 1 is advanced along the guide wire w, and the tip of the screw portion 12 is inserted into the prepared hole h. By providing the guide hole 15 in this manner, when the working part provided with the prepared hole h is a deep part or a small part of the body and it is difficult to insert the tip of the screw portion 12 into the prepared hole h However, it is possible to easily insert the tip of the screw portion 12 into the pilot hole h using the guide wire w. However, when the working portion is relatively shallow and the tip of the screw portion 12 can be easily inserted into the prepared hole h, there is no need to use the guide wire w.

When the tip of the screw portion 12 is inserted into the prepared hole h,
By rotating the handle 13 clockwise, the screw portion 12 is rotated to form a female screw in the bone X. When this operation is described in detail, the blades 14, 14,
The cutting blades 14c, 14c,... Move spirally to cut the bone X to form a thread groove. At this time, since the outer diameter of the screw portion 12 is formed so as to decrease on the tip side, a shallow screw groove is formed at first, and a deeper screw groove is gradually formed as the screw portion 12 moves forward. Go.

When the blades 14, 14,... Cut the bone X to form a thread groove, shavings d are generated. The cuttings d are powder, and the bodily fluid contained in the bone and the lower It mixes with the bodily fluid flowing into the hole h to form a semi-fluid or very brittle powder mass, and is pressed against the rake face of the blade portion 14 and the bottom surface of the thread groove, as shown in FIG. Shaft 11
It is pushed out to the side. As the screw portion 12 rotates, the chip d extruded toward the shaft body 11 moves along a spirally formed groove portion of the screw portion 12 and is discharged backward.

The screw groove is formed by such an operation, and when the orthopedic tap 1 is advanced to a desired depth, the rotation of the handle 13 is stopped. The determination as to whether or not the orthopedic tap 1 has reached a desired depth is made by the threaded portion 1 of the shaft 11.
The determination is made based on whether or not the scale indicating the desired depth among the scales 17 provided in the vicinity of 2 has reached the entrance of the prepared hole h. Also, the entrance of the prepared hole h is at a deep part of the body, etc.
In the case where it is not possible to visually check whether or not the entrance of the orthopedic surgical tap 1 has been reached, it is possible to determine whether or not the orthopedic tap 1 has reached the desired depth by using the marker 16 provided on the side of the handle 13. It is. That is, since the pitch of the female screw to be formed is fixed, the depth can be calculated by counting the number of times the marker 16 appears with the rotation of the handle 13 and counting the number of rotations of the handle 13. Therefore, the number of rotations corresponding to the desired depth is calculated in advance, and the number of rotations is counted using the marker 16, so that tapping to the desired depth can be performed. Further, the marker 16 can determine the depth more finely than the scale 17, and is also useful when it is necessary to determine the depth more delicately than the scale 17.

After the above steps, the wire w is pulled out, and the handle 13 is rotated counterclockwise so that the screw portion 12 is released from the formed internal thread, so that the orthopedic tap 1 is released from the pilot hole h. Thereby, the formation of the female screw on the bone X is completed.

[0022]

As described above, the present invention has the following effects. First, when the tapping is performed on the bone body by the orthopedic tap according to the present application, the thread groove is cut by the blade portion spirally provided at the tip of the shaft body,
The swarf of the bone is pushed out toward the shaft, and is discharged backward along the spiral groove formed continuously.
On the other hand, by continuously forming the rake face and the flank face of each of the adjacent blade portions, it is possible to prevent ligaments, muscles, and the like from being entangled or cut between the blade portions.
That is, with the orthopedic tap according to the present application, the tapping operation can be performed on the bone body without damaging the soft tissue in the body and without accumulating in the thread groove formed by the chips.

Further, by forming the height of the spirally provided blade portion toward the tip of the shaft body, the screw groove formed by the blade portion near the tip of the tap is shallow, and Since the thread groove formed gradually proceeds toward the edge portion on the end side, the target female screw can be formed by a single tapping operation while reducing the cutting resistance.

When a hole is provided through the shaft portion of the shaft, a guide wire passed through a pilot hole provided at a portion where a female screw is formed is inserted into the hole from the tip of the shaft. If the orthopedic tap of the present application is advanced along the guide wire, the distal end of the shaft body can be easily guided to the portion where the female screw is formed, and the tapping operation can be easily performed.

Further, by providing a marker for counting the number of rotations on a handle provided at the base of the shaft or a part of the outer peripheral surface of the shaft, how many times the tap has been rotated when performing the tapping operation. Counting is facilitated, so that the user can easily know how far the tap has advanced. In addition, by forming the handle into a bar shape and forming the cross-sectional shape to be horizontally long, a user can grip the bar-shaped handle firmly using the entire palm, and rotate the cross-sectional shape by making the cross-sectional shape horizontal. A force can be exerted away from the axis and the orthopedic tap can be rotated with a strong torque.

[Brief description of the drawings]

FIG. 1A is a front view of an orthopedic tap according to the present invention, and FIG. 1B is a side view of the orthopedic tap according to the present invention.

2 (a) is an enlarged front view of a distal end portion of an orthopedic tap according to the present invention, and FIG. 2 (b) is an enlarged plan view of a distal end portion of the orthopedic tap according to the present invention.

3 (a) to 3 (c) are views showing variations of the thread portion of the orthopedic tap according to the present invention.

FIG. 4 is a view showing a usage mode of the orthopedic tap according to the present invention.

FIG. 5 is a front view showing a conventional orthopedic tap.

FIG. 6 (a) is an enlarged view of a distal end portion of a conventional orthopedic tap, and FIG. 6 (b) is a sectional view taken along line AA in FIG. 6 (a).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Orthopedic tap 11 Shaft 12 Screw part 13 Handle 14 Blade part 14a Rake surface 14b Flank surface 14c Cutting edge 15 Guide hole 16 Marker 17 Scale

Continued on the front page (72) Inventor Kazuo Kaihira 22-7 Ichijoji Nishiurahatacho, Sakyo-ku, Kyoto-shi

Claims (5)

[Claims] 1. A plurality of blades are provided spirally at the tip of a shaft body,
An orthopedic tap formed by continuously forming the rake face and flank face of each adjacent blade. 2. The orthopedic tap according to claim 1, wherein the height of the spirally provided blade portion decreases toward the distal end of the shaft body. 3. The orthopedic tap according to claim 1, wherein a hole penetrating through an axial portion of the shaft body is provided. 4. A handle provided at a base of the shaft, or
The orthopedic tap according to any one of claims 1 to 3, wherein a marker for counting the number of rotations is provided on a part of the outer peripheral surface of the shaft body. 5. The orthopedic tap according to claim 4, wherein the handle is rod-shaped, and has a horizontally long cross-sectional shape.