JP2013099371A - Medical drill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a medical (surgical) drill which is hard to break during drilling and is capable of drilling a bent hole.SOLUTION: The medical drill 1 has a cutting blade 1a for drilling formed at a distal end and is capable of performing drilling by rotation, and at least a shaft part 1B extending in the axial direction of the drill 1 is constituted of a superelastic alloy. For the drill 1, a cutting blade part 1A is formed at the distal end part, and a discharge groove 1b for discharging cutting waste to a proximal end part (drilling hole outer part) is formed adjacently to the cutting blade 1a at the rotating direction front of the cutting blade 1a of the cutting blade part 1A.

Description

  The present invention relates to a medical drill used for drilling a bone or the like in a surgical operation or the like.

  Conventionally, medical drills have been used for surgery and the like. For example, when an arm or a leg is fractured, the fracture part is connected (coupled) with a metal fitting to be reinforced. In such a case, the bone before and after the fracture site is drilled with a medical drill, and the metal fitting is fixed to the drilled hole with a screw or the like, and the fractured bones on both sides are fixed.

Conventionally, as a medical drill used for drilling such a bone, the same material as a drill used for woodworking work or metalworking work, such as high-speed tool steel or stainless steel, has been used. (See Patent Document 1).
Japanese Patent Application Laid-Open No. 2010-279539.

  By the way, in the above-mentioned drill, since the material with high hardness, such as high-speed tool steel, is used for the material, when the external force in the direction having the crossing angle in the axial direction of the drill acts on the drill, the drill breaks. was there.

  In this way, if the drill breaks during drilling in the bone in surgery, a broken piece of the drill must be taken out from the hole being drilled, which adds to the troublesome work in addition to the normal surgical work. Will be.

  On the other hand, when drilling into a bone or the like, there is a case where it is desired to drill in a state where the longitudinal direction of the hole is curved. In such a case, an external force is applied to the drill during drilling in a direction having an angle of intersection in the axial direction. While making it act, it may be perforated.

  The present invention has been made in view of such a situation, and an object of the present invention is to provide a medical drill that is hard to break even when an external force acts in a direction having an angle of intersection in the axial direction.

A medical instrument according to the present invention is a medical (surgical) drill capable of performing drilling by rotation with a cutting edge for drilling formed at the tip,
A shaft portion extending at least in the axial direction of the drill is made of a superelastic alloy.

  Thus, according to the medical drill, since at least the shaft portion extending in the axial direction of the drill is made of a superelastic alloy, it is necessary to drill a hole in the bone whose longitudinal direction is curved in surgery. Or even if unintentionally (accidentally) an external force in a direction that has an angle of intersection in the axial direction is applied to the drill, or a buckling load may be applied, Will not bend and break.

  In addition, when the cutting edge is formed by attaching a cemented carbide tip to the cutting edge portion of the drill tip, the medical drill is positioned toward the tip of the shaft portion, high cutting performance And a durable drill.

  The medical drill is located at the tip of the shaft, and when the treatment for increasing the hardness is performed by coating the cutting edge portion of the drill tip, the drill having high cutting performance and durability, Become.

  In the medical drill, it is preferable that the superelastic alloy is a nickel titanium alloy because it is a material that can be easily obtained at a relatively low cost.

  According to the medical drill configured as described above, it is possible to provide a medical drill that is not easily broken during drilling.

It is a perspective view which shows the whole structure of the medical drill concerning the Example of this invention. It is a partial expansion perspective view which shows the structure of the front-end | tip part of the medical drill shown in FIG. FIG. 4 is a partially enlarged perspective view of a distal end portion of a medical drill according to another embodiment different from FIG. 2.

Hereinafter, a medical drill according to an embodiment of the present invention will be described more specifically based on the drawings.
Example 1
1 and 2, reference numeral 1 denotes a medical (surgical) drill used for drilling a bone or the like. The drill 1 has a cutting edge portion 1 </ b> A formed at a distal end portion of the cutting blade portion 1 </ b> A. In front of the cutting blade 1a in the rotation direction, a discharge groove 1b is formed adjacent to the cutting blade 1a to discharge chips to the base end (outward of the hole). The discharge groove 1b is formed by a predetermined length in the axial direction from the cutting edge portion 1A to the shaft portion 1B adjacent to the base end. In this embodiment, the discharge groove 1b is recessed in the outer peripheral surface 1F of the drill 1 so as to have a spiral shape with a predetermined angle (approximately 60 degrees in this embodiment) with respect to the direction perpendicular to the axis. Has been.

In the case of this embodiment, a super elastic alloy is used for the cutting blade portion 1A and the shaft portion 1B other than the cutting blade 1a of the cutting blade portion 1A of the drill 1, that is, the cutting blade portion 1A and the shaft portion 1B of the drill 1 in this embodiment. Yes.
On the other hand, in this embodiment, the cutting blade 1a is formed by embedding a block-shaped cemented carbide chip 1c in the outer edge portion of the tip portion of the cutting blade portion 1A. As the cutting blade 1a, a tip made of high-speed tool steel may be used instead of the cemented carbide tip 1c.
The chip 1c has a recess formed in the cutting edge portion 1A, and is integrally attached to the recess by brazing.

  In this embodiment, a nickel titanium alloy is used as the superelastic alloy. However, the nickel titanium alloy is preferable in that it does not easily cause an allergic reaction to a living body.

However, as another example, as shown in FIG. 3, the entire cutting blade portion 1A including the cutting blade 1a is integrally molded (integrated casting) with a high hardness material such as high-speed tool steel or stainless steel, By using a superelastic alloy for the shaft portion 1B at the proximal end, brazing the proximal end of the cutting blade portion 1A and the tip of the shaft portion 1B, or by laser welding or plasma welding, etc. You may comprise the drill 1 by connecting integrally. In addition, about the same structure as the drill 1 concerning the Example shown in FIG. 1, FIG. 2, the same referential mark is attached | subjected and the description is abbreviate | omitted.
In this case, if the connecting portion 1t between the base end of the cutting blade portion 1A and the tip end of the shaft portion 1B is configured to have a larger diameter than the outer diameter of the shaft portion 1B, it will have an angle of intersection in the axial direction. Even if an external force is applied, the bending is performed only at the shaft portion 1B having lower rigidity to absorb the external force, and the cutting blade portion 1A is hardly subjected to bending or distortion due to the external force. This is a preferred embodiment.

  Alternatively, the entire drill may be formed of a superelastic alloy, and the cutting edge 1a may be coated to increase the hardness of the cutting edge 1a and improve the drilling performance. For example, it is desirable that the ion plate is coated as a coating process.

As the stainless steel used for the cutting edge portion 1A, “SUS630”, “SUS420J2”, “SUS440C” or the like that can increase the hardness by heat treatment is preferably used.
As the superelastic alloy, a nickel titanium alloy is preferable for the same reason as described above.

Therefore, the medical drill 1 according to the present embodiment configured as described above operates as follows. That means
When such a drill 1 is used to make a hole in a bone, for example, a fractured human femur, and connect a fractured part with a metal plate, the hole drilled by the drill 1 is slightly opened in the longitudinal direction of the hole. Even when drilling while applying an external force in a direction having an angle of intersection in the axial direction of the drill 1 when it is desired to bend and clear, the shaft portion 1B of the drill 1 can be easily bent within an elastic range according to the external force. it can. For this reason, drilling can be performed without breaking the drill 1.

  In addition, the cutting blade 1a is made of high-speed tool steel, stainless steel, or a cemented carbide tip having a higher hardness than the superelastic alloy of the shaft portion 1B, or the surface of the cutting blade is coated. Therefore, it also has high drilling ability.

  For this reason, such a drill is an optimum drill as a medical drill for drilling bone in surgery.

  Further, the present invention is not limited to the above-described embodiments, and it goes without saying that the present invention can be implemented in various forms within the scope based on the technical idea of the present invention.

  The medical drill according to the present invention can be widely used in the medical industry field.

1 ... Medical drill
1A ... Cutting blade part
1B ... Shaft
1a ... Cutting blade
1b ... discharge groove

Claims (4)

A medical drill capable of drilling by rotation with a cutting edge for drilling formed at the tip,
A medical drill characterized in that at least a shaft portion of the drill extending in the axial direction of the drill is made of a superelastic alloy.   2. The medical blade according to claim 1, wherein the cutting blade is formed by attaching a cemented carbide tip to a cutting blade portion of a drill tip located at the tip of the shaft portion. 3. drill.   The medical drill according to claim 1, wherein a treatment for increasing the hardness is performed by coating a cutting edge portion of the drill tip portion located at the tip portion of the shaft portion.   The medical drill according to any one of claims 1 to 3, wherein the superelastic alloy is a nickel titanium alloy.

Images