JP3212701U - Cutting tools and instruments for machining artificial bones - Google Patents

Abstract

A cutting tool capable of easily providing a hole in an artificial bone without being an expert and an instrument for processing an artificial bone provided with the cutting tool are provided. A cutting tool (drill 30) for making a hole in an artificial bone to be compensated for a bone defect caused by osteotomy, a shank 31 to which a rotational force about an axis is applied, and a position in front of the shank A thin shaft neck 33 to be inserted into the artificial bone, and a stopper 32 provided at a boundary position between the neck and the shank and formed on a thicker shaft than the neck so as to contact the surface of the artificial bone. . The outer diameter of the neck is in the range of 0.8 mm to 1.2 mm. [Selection] Figure 2

Description

  The present invention relates to a cutting tool and an instrument for artificial bone processing, and more particularly, to a cutting tool and an instrument for artificial bone processing for making a hole in an artificial bone to be compensated for a bone defect portion generated by osteotomy.

  One of the treatments for medial osteoarthritis of the knee in the orthopedic field is high tibial osteotomy (HTO). In this method, a wedge-shaped bone defect portion is formed by cutting inside the tibia, and then an artificial bone is supplemented to the bone defect portion to adjust the angle of the tibia. As a result, the center of gravity that is too biased toward the inside of the knee can be moved outward.

  For example, Patent Document 1 discloses a structure of an artificial bone (bone filling material). Specifically, it is formed in a wedge-shaped block shape that matches the shape of the bone defect portion, with one end of the wedge shape having a thickness of 0.5 mm or less and the other end of the wedge shape having a thickness of about 2.0 mm to 14 mm. Has been.

JP 2014-54458 A

Here, in order to promote the fusion between the bone (osteotomy surface) and the artificial bone, a plurality of small shallow holes (for example, an outer diameter of about 1 mm and a depth of about 3 mm to 5 mm) may be provided in advance in the artificial bone. is there. In this case, the artificial bone is cut from the front surface and the back surface of the artificial bone with a drill.
However, it is difficult to provide a plurality of holes having the same depth, and the practitioner is required to have skills.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a cutting tool and an artificial bone processing instrument that can easily provide a hole in an artificial bone without being an expert. And

  In order to solve the above-mentioned problems, the invention of claim 1 is a cutting tool for making a hole in an artificial bone that is to be compensated for a bone defect generated by osteotomy, and the cutting tool has a rotational force around an axis. A shank to be applied, a neck portion of a thin shaft that is positioned in front of the shank and inserted into the artificial bone, and provided at a boundary position between the neck portion and the shank, and is formed with a thicker shaft than the neck portion. And a stopper capable of contacting the surface of the artificial bone, wherein the outer diameter of the neck is in the range of 0.8 mm to 1.2 mm.

  The device of claim 2 is characterized in that, in the device of claim 1, the length of the neck is in the range of 3 mm to 5 mm.

  The invention of claim 3 is characterized in that in the invention of claim 1 or 2, the stopper is formed larger than the outer diameter of the shank.

  The invention of claim 4 is characterized in that, in the invention of any one of claims 1 to 3, the stopper has a chamfered portion at a boundary position with the shank.

  The invention of claim 5 is characterized in that, in the invention of any one of claims 1 to 4, the neck portion is formed of a material different from that of the shank.

  The invention of claim 6 is an instrument for artificial bone processing comprising the above cutting tool, and a handpiece for detachably mounting the cutting tool and rotating the cutting tool. Is.

  According to the present invention, the stopper is provided at the base of the neck, and the stopper contacts the surface of the artificial bone when drilling. Therefore, even if it is not an expert, a hole can be easily provided in an artificial bone.

It is an external appearance perspective view of the instrument for artificial bone processing of this invention. It is a figure explaining the cutting tool of 1st Example. It is a figure explaining the cutting tool of 2nd Example. It is a figure explaining the cutting tool of 3rd Example. It is a figure explaining the cutting tool of 4th Example.

The cutting tool and artificial bone processing instrument of the present invention will be described below with reference to the drawings. FIG. 1 is an external perspective view of the artificial bone processing instrument of the present invention.
The artificial bone processing instrument 1 has a hand piece 2, and the hand piece 2 is connected to the apparatus main body 4 via a cord 3.

For example, a speed adjustment knob 4a is provided on the front surface of the apparatus main body 4, and the apparatus main body 4 is connected to the foot controller 6 via, for example, a cord 5 drawn from the back surface thereof. The speed adjusting knob 4a can adjust the maximum speed when the foot controller 6 is depressed.
The handpiece 2 includes a head portion 21 and a grip portion 22, and a sleeve (not shown), for example, in which a drill 30 can be detachably attached is provided inside the head portion 21.

  The grip portion 22 is located behind the head portion 21, and a motor (not shown) that drives the sleeve with the power of, for example, a spindle or an AC power source is provided inside the grip portion 22. Thereby, the rotation of the motor is transmitted to the drill 30 via the spindle and the sleeve. The drill 30 corresponds to the cutting tool of the present invention. The drill may be rotated by air instead of the motor.

(First embodiment)
2A and 2B are diagrams for explaining the cutting tool of the first embodiment, in which FIGS. 2A and 2B are plan views and FIG. 2C is a front view. Note that FIG. 2B is obtained by rotating FIG. 2A by 90 °.
The drill 30 is made of, for example, tool steel such as high speed steel, and has, for example, a solid round bar shank 31 attached to the sleeve of the head portion 21 described in FIG. The shank 31 is given a rotational force around the axis from the motor.

In front of the shank 31, a narrow shaft neck 33 having a smaller diameter than the outer diameter of the shank 31 is provided, and a stopper 32 having a thicker shaft than the neck 33 is provided at a boundary position between the neck 33 and the shank 31. It has been. As shown in FIG. 2C, the neck 33 and the stopper 32 are concentric with the shank 31.
The neck 33 can be inserted into the artificial bone, and the length from the blade tip to the root is formed in the range of 3 mm to 5 mm, for example. If it is this length, it can respond to the drilling of various artificial bones from which thickness differs with one drill 30. Note that it may be shorter than 3 mm as required.

Further, the outer diameter of the neck portion 33 is formed in the range of 0.8 mm to 1.2 mm, and it is possible to provide the artificial bone with a hole that is easily invaded by bone tissue.
The chip discharge groove 34 is a stepped columnar primary processing material (blank material) composed of a small diameter portion (outer diameter φ1 mm) corresponding to the neck 33 and a large diameter portion (outer diameter φ2.35 mm) corresponding to the shank 31. It is also formed by grinding, for example, with a grinding wheel.

  Specifically, the grinding wheel is tilted with respect to the axis of the neck 33 and set at a position where it can contact the front end of the neck 33. Next, when the grinding wheel is rotated and, for example, the edge of the outer peripheral surface of the grinding wheel comes into contact with the front end of the neck portion 33, when the neck portion 33 is advanced at a predetermined speed while rotating at a predetermined speed, A chip discharge groove 34 is formed. Thereafter, when the neck 33 is rotated 180 ° and processed in the same manner as described above, a second chip discharge groove 34 is formed.

  The length of the chip discharge groove 34 in the axial direction is about 3.5 mm. As shown in FIGS. 2A and 2B, a part of the chip discharge groove 34 reaches the shank 31. Yes. The twist angle of the chip discharge groove 34 is, for example, about 11 ° with respect to the axis of the neck 33. Due to the formation of the two chip discharge grooves 34, a curved land is formed between the chip discharge grooves 34.

Further, the mountain-shaped cutting edge 35 is formed by, for example, forming the chip discharge groove 34 and then grinding the front end of the neck portion 33 by, for example, the front surface of the finishing grinding wheel. The tip angle of the cutting edge 35 is about 118 °.
And if the drill 30 of this invention is used, the instrument for artificial bone processing which can provide a hole in an artificial bone easily can be provided.

  Specifically, the drill 30 is set on the handpiece 2, and after the drilling position is determined on the surface of the artificial bone, the foot controller 6 is stepped on and the drill 30 is rotated. Next, the tip of the rotated drill 30 is advanced from the surface of the artificial bone toward the inside. Subsequently, when the stopper 32 comes into contact with the surface of the artificial bone, the drill 30 idles, so that the foot controller 6 is stopped.

Thus, the stopper 32 contacts the surface of the artificial bone when drilling. Therefore, even if it is not an expert, a hole can be easily provided in an artificial bone.
In addition, when the endurance test of this drill 30 was carried out, when the artificial bone was drilled up to the 100th hole, some abrasion was seen on the cutting edge. There was almost no change even when a hole was made.

(Second embodiment)
FIG. 3 is a diagram for explaining the cutting tool of the second embodiment.
The drill 30 of the first embodiment has been described with an example in which the stopper 32 has the same outer diameter as the shank 31. However, the present invention is not limited to this example. For example, as shown in FIG. 3, a stopper 32A larger than the outer diameter of the shank 31 may be formed. At the time of drilling, the stopper 32A easily comes into contact with the surface of the artificial bone, so that the depth of the hole can be more reliably regulated.

(Third embodiment)
FIG. 4 is a diagram for explaining a cutting tool according to the third embodiment. As shown in the figure, a chamfered portion 36 having an R-shaped cross section, for example, may be provided at the boundary position between the shank 31 and the stopper 32. In this case, even if the neck portion 33 is inserted into the artificial bone with the neck portion 33 being inclined, the chamfered portion 36 abuts on the surface of the artificial bone, so that the artificial bone can be prevented from being damaged.

(Fourth embodiment)
FIG. 5 is a diagram for explaining a cutting tool according to the fourth embodiment. The neck 33A is brazed to the shank 31A, for example, and the neck 33A is formed of a material different from that of the shank 31A. Specifically, the neck 33A and the shank 31A can be formed of a material suitable for each purpose, for example, the neck 33A is formed of tool steel and the shank 31A is formed of stainless steel.

DESCRIPTION OF SYMBOLS 1 ... Instrument for artificial bone processing, 2 ... Hand piece, 3 ... Cord, 4 ... Apparatus main body, 4a ... Knob for speed adjustment, 5 ... Cord, 6 ... Foot controller, 21 ... Head part, 22 ... Grip part, DESCRIPTION OF SYMBOLS 30 ... Drill, 31, 31A ... Shank, 32, 32A ... Stopper, 33, 33A ... Neck part, 34 ... Chip discharge groove, 35 ... Cutting blade, 36 ... Chamfering part

Claims (6)

A cutting tool that drills a hole in an artificial bone that fills a bone defect caused by osteotomy,
The cutting tool is provided at a shank to which a rotational force about an axis is applied, a neck of a thin shaft that is inserted in the artificial bone in front of the shank, and a boundary position between the neck and the shank. A stopper formed on a thicker shaft than the neck and capable of contacting the surface of the artificial bone,
A cutting tool characterized in that the outer diameter of the neck is in the range of 0.8 mm to 1.2 mm.   The cutting tool according to claim 1, wherein the length of the neck is in the range of 3 mm to 5 mm.   The cutting tool according to claim 1 or 2, wherein the stopper is formed larger than the outer diameter of the shank.   The cutting tool according to any one of claims 1 to 3, wherein the stopper has a chamfered portion at a boundary position with the shank.   The cutting tool according to any one of claims 1 to 4, wherein the neck is formed of a material different from that of the shank.   6. An artificial bone machining-in, comprising: the cutting tool according to any one of claims 1 to 5; and a handpiece for detachably mounting the cutting tool and rotating the cutting tool. Instrument.

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