JP2003245283A - Perforating direction variable drill - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drill which can be transferred to a perforating work immediately when the edge is completely registered without forming a guide hole as the edge used mainly for a treatment or the like of a fracture and in which the perforated position or the perforating direction can be corrected while the work is continued even after the work is started. <P>SOLUTION: The drill edge 1 comprises a multidirectional perforating edge 3 having a smaller perforating diameter and flat section than those of the edge 1 provided at the distal end of the spiral edge 1, and a perforating position holding blade 2 provided at the distal end of the multidirectional perforating edge 3. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drill blade mainly used for forming a bone hole in a surgical procedure such as a fracture procedure.

[0002]

2. Description of the Related Art Reinforcing methods using intramedullary nails are widely used in the treatment of fractures of the femur and tibia. Figure 13
Fig. 3 shows a state in which a long bone in a fractured state treated by the reinforcing method is fixed. Fractures of the femur and tibia 10
An intramedullary nail 11 is inserted and placed under anesthesia into the bone marrow of the bone 10 to reinforce a. Since the intramedullary nail 11 is fixed to the bone 10 by using the lateral set screw 12 in order to increase rigidity and stability at the time of fixing, the insertion hole for inserting the set screw 12 is provided.
It has a plurality of 13. The diameter of the intramedullary nail 11 is set so that it can be accommodated in the bone marrow.

As described above, although the intramedullary nail 11 has a linear fixing structure, it has flexibility (suppleness) to the extent that it can be twisted while it is inserted into the bone marrow, so that it remains inside the bone marrow. It is extremely difficult to confirm the insertion hole 13 for inserting the set screw 12 after the intramedullary nail 11 is arranged. In particular, since the intramedullary nail 11 is located inside the bone, it is not possible to find the insertion hole 13 from the outside of the bone by direct measurement using a familiar jig, so use a jig as shown in FIG. Was being done. That is, in the jig J having a substantially U-shape in a side view, the guide hole J13 is formed in the lower arm J1 at a position corresponding to the insertion hole 13 in the intramedullary nail 11, so that the bone marrow inserted into the bone marrow is inserted. When the inner nail 11 and the arm J1 of the jig J are kept in parallel, the guide hole J13 in the arm J1 and the insertion hole 13 of the intramedullary nail 11 are aligned (FIG. 14).
(Refer to (b)), if you drill a hole from the guide hole J13,
The set screw 12 penetrating both holes can be screwed in.

However, since the insertion hole 13 on the peripheral side is located far from the base of the jig J, if the intramedullary nail 11 is bent in the bone marrow, it cannot be kept parallel to the jig J. Therefore, in such a state, the drill blade is moved to the guide hole J13 of the jig J.
Even if the bone 10 is pierced along the bone, it will be displaced from the insertion hole 13 provided in the intramedullary nail 11 (see FIG. 14 (c)).

Therefore, in the recent medical field, perforation positioning is performed by a radiolucent drill using a monitoring image (image) of an X-ray image amplification device. FIG. 15 is a schematic view showing a state of a drilling work with a radiolucent drill, and after drilling with a drill blade for screwing the set screw 12 toward the insertion hole 13 after the intramedullary nail 11 is placed in the bone marrow. It shows the situation. First, the part of the skin corresponding to the position of the insertion hole 13 in the intramedullary nail 11 is confirmed by visually referring to the monitor image of the X-ray image intensifier. The skin, fascia, and muscle are sequentially incised with a scalpel, and a drill blade is inserted into the incision site.
After inserting the drill blade, the tip of the drill blade 14 cannot be visually confirmed. Therefore, the drill blade tip is obliquely directed to the surface of the bone 10, and the drill is visually referred to the monitor image of the image intensifier by the X-ray beam. The cutting edge is accurately aligned with the insertion hole 13. In the surveillance image, the insertion hole 13 appears as a white circle, while the drill blade appears as a black shadow, so that it is possible to confirm whether or not accurate alignment has been achieved by overlapping the two.

FIG. 16 is a diagram showing a drilling process using a drill blade. Insert the insertion hole 13 at the tip with the drill blade 14 inclined.
When the alignment is completed so as to match (Fig. 16 (a)),
As shown in FIG. 16 (b), the drill blade 14 is erected in the drilling direction while the drill blade tip is not moved. Then, as shown in FIG. 16 (c), the drill blade 14 is rotated to perforate the front and rear bones of the insertion hole 13 of the intramedullary nail 11. As a preparation for drilling with such a radiolucent drill, in order to prevent the drill from sliding laterally on the surface of the bone, a sharp cone placed in the drilling direction is used to pre-depress it to the insertion position (center). Punching (marking) or a method in which a thin steel wire is used and a guide hole is provided in advance and a drill is performed based on the guide hole is performed.

[0007]

As described above, in the work of visually referring to the image of the image amplifying apparatus using the X-ray beam, the practitioner continues to receive the irradiation of the X-ray beam until the completion of the drilling work. Therefore, if the drilling operation is performed for a long time, the amount of radiation will increase, and there is a concern that the health of the practitioner will be affected. Immediately after the start of drilling work, the problem is that the drill blade is often not perpendicular to the bone surface due to the bone shape, the drilling position is easily displaced, and the strength of the skin, fascia, periosteum, etc. It is a point that a high-tissue structure easily acts in the direction in which the drill cutting edge is displaced. Once the drill blade is displaced from the correct drilling position, it is no longer possible to correct the drilling direction.

[0008] Therefore, the present inventors, after finishing the position alignment of the drill blade, can directly proceed to the drilling work, and further, even after the drilling work is started, the drilling position and the drilling direction are maintained while continuing the drilling work. We investigated a drill blade that can correct the above-mentioned problem and can drill the bone through the insertion hole of the intramedullary nail to the bone on the opposite side.

[0009]

In order to solve the above problems, according to the present invention, a multi-directional piercing blade having a small piercing diameter and a flat cross section is provided at the tip of the piercing blade, and a piercing position holding blade is further provided at the tip. It was a drill bit with variable drilling direction. Here, the multidirectional piercing blade has a cross section of a substantially rectangular shape, that is, one having two parallel surfaces facing each other, or a concave groove or a ridge extending in the piercing direction is provided on the side wall surface thereof. Depending on the case, the one with a concave lens-shaped cross section, or the one with the central shaft part and the left and right piercing blade parts bulging outward, etc. are exemplified, and from the base side of the spiral piercing blade to the tip side. It is desirable to form so that the diameter becomes as small as possible. The base maximum diameter of this multidirectional piercing blade is
It is preferable that the diameter of the perforating blade, which will be described later, be about 1/4 to 9/10.

The perforation position holding blade is formed into a pointed pyramid shape having a smaller perforation diameter toward the tip, and a polygonal cross section having a substantially triangular shape or more, or a shape in which a concave groove or a ridge is provided. Good to do. Further, the tip angle of the punching position holding blade is 50 ° to
90 is preferred.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an enlarged side view of essential parts showing one embodiment of a drill bit with variable drilling direction according to the present invention. FIG. 2 is an enlarged side view of the main part when rotated a little, and FIG. 3 is an enlarged side view of the main part when rotated by 90 °. 4A is a sectional view taken along the line AA in FIG. 3, and FIG. 4B is a sectional view taken along the line BB in FIG. In the drilling direction variable drill blade of the illustrated example, the structure of rake angle, clearance angle, etc. regarding the shape of the spirally shaped drilling blade 1 on the main body side is not particularly limited, and conventional drilling efficiency, operability , The degree to which the drilling accuracy is considered good (for example, the rake angle is -5
The angle is set to 40 ° and the clearance angle is set to 20 °. Also,
The number of rows of the piercing blade 1 can be set within the range of 1 to 6 depending on the piercing efficiency, operability, piercing accuracy and the like.

A feature of the drilling direction variable drill blade of the present invention is that a multidirectional drilling blade 3 having a flattening cross section and a smaller drilling diameter than the drilling blade 1 is provided at the tip of the drilling blade 1. The position holding blade 2 is provided. In this example, the punching position holding blade 2 has a triangular shape in a side view whose diameter becomes smaller toward the tip, and the horizontal cross section of the punching position holding blade 2 is a square pyramid as shown in FIG. 4A. When the pyramid is used as described above, the positioning of the cutting edge is easy and the drilling efficiency is good. To further improve the drilling efficiency, etc., see FIG.
It is advisable to provide a recess on the side wall surface as in (a).

Multidirectional drilling blade 3 in the drill blade of this example
As shown in Fig. 4 (b), the flat cross section, that is, the cross section is a substantially rectangular shape, and the blade portions 4 are provided at the corners while forming a reinforcing structure in which concave grooves and convex strips are provided on two opposing surfaces. It is a structure. In the illustrated example, the base maximum diameter d (16 mm) of the multidirectional piercing blade 3
Is 1/2 of the diameter D (32 mm) of the hole. Also,
The tip angle of the drilling position holding blade 2 is approximately 60 °, and the multidirectional drilling blade 3
The total rising height H from the drilling blade including 11 is 11 mm.

By providing the multidirectional piercing blade 3, when the tip position of the piercing position holding blade 2 deviates from the center S of the insertion hole 13 of the intramedullary nail 11 during the piercing work, it will be described in detail later. A correction function by moving in the horizontal direction is added. Not only the work from the guide hole drilling for the bone hole to the drill drilling can be smoothly carried out, but also the drilling position can be finely corrected while suppressing unnecessary damage to the bone material.

This will be further explained with reference to the drawings.
As shown in FIGS. 5 to 8, when the multi-directional perforation blade 3 having a small perforation diameter and a flat cross section is provided at the tip of the perforation blade 1 as in the present invention, and the perforation position holding blade 2 having the smaller perforation diameter is further provided at the tip thereof. As shown, the bone is
It is possible to make a hole in the hole 10, and it is also possible to perform a hole position correcting operation as shown in FIGS. In each figure, (a) is a side view showing the relationship between the drilling direction of the bone and the drill cutting edge, and (b) shows the state of the monitoring image of the image amplifying device by the X-ray beam.

First, to explain the perforation method shown in FIGS. 5 to 8, the practitioner inserts the intramedullary nail 11 by tilting the drill axis O as shown in FIG. 5 while watching the monitoring image of the image amplification device. Hole
The position of the drilling position holding blade 2 at the tip of the drill is aligned with the center S of 13. When the alignment of the cutting edges is completed, the drill axis O is raised in the drilling direction as shown in FIG. In this case, since the drill cutting edge has the sharp conical drilling position holding blade 2, it is possible to cause the drill axis O in the drilling direction while maintaining an accurate position without sliding sideways. And
As shown in FIG. 7, the multidirectional piercing blade 3 starts piercing while rotating and pressing, and when the urging and pressing is further continued, the original piercing by the piercing blade 1 starts and the intramedullary nail as shown in FIG. It is possible to make holes at precise positions toward the insertion holes 13 of 11. As described above, if the tip position of the drilling position holding blade 2 of the drill blade does not deviate from the axial direction under the monitoring of the monitoring image, the rotation pressing is continued and the insertion hole 13 of the intramedullary nail 11 is inserted.
A bone hole that communicates with is formed.

9 to 12 show a drilling position correcting method which is made possible for the first time by using the drilling direction variable drill blade of the present invention. As shown in FIG. 9, when the drill is rotated and pressed to start the drilling work, the tip position of the drilling position holding blade 2 which is the cutting edge is displaced from the center S of the insertion hole 13 of the intramedullary nail 11. In the case of a conventional drill blade, there was no choice but to start over from the positioning work of the cutting edge.
With the drill blade according to the present invention, the drilling direction can be corrected to the correct direction while continuing the drilling operation.

That is, when the drill shaft O is tilted again toward the center S of the insertion hole 13 and rotated and pressed from the state shown in FIG. 9 as shown in FIG. 10, the multidirectional piercing blade 3 cuts bone. However, the cutting edge moves to the center position of the insertion hole 13 where the original position should be (FIG. 11). After confirming that the tip of the drilling position holding blade 2 has reached the target center position of the insertion hole 13 by the monitoring image, the drill axis O is caused to coincide with the accurate drilling direction as shown in FIG. If the boring operation is continued, the desired bone hole can be easily bored. Since the multidirectional piercing blade 3 has a smaller piercing diameter than the spiral piercing blade 1 of the drill blade body, the portion cut by the multidirectional piercing blade 3 during the above-described piercing direction correcting work is the piercing blade 1 Will be contained within the perforations made by. In this way, by tilting or causing the drill blade to lie down, it is possible to easily correct the drilling direction of the drill blade so as to match the originally intended drilling direction.

[0019]

Since the drilling direction variable drill blade according to the present invention is provided with the drilling position holding blade at the tip, it is possible to substantially prevent the drill blade from sliding sideways. Therefore, the preparation step of the drilling work, that is, the complicated work of forming a recess for guiding the drilling direction on the bone surface with a cone or previously drilling a thin bone hole with a steel wire is unnecessary. In addition, the labor for preventing the skid blade from slipping, and the labor for readjusting the tip position and the drilling direction when the drill blade slips are eliminated.

Since the multidirectional piercing blade is provided between the piercing position holding blade and the spiral piercing blade, the tip of the piercing position holding blade is displaced from the center S of the insertion hole of the intramedullary nail. Even if the drill blade is tilted or laid down so that it lays down, the drill blade tip can be easily moved to the target position while continuing the drilling work without separating it from the bone to correct the drilling direction. It is possible.

Therefore, it is possible to shorten the drilling work time while receiving continuous X-ray irradiation, and reduce the risk of exposure not only to the surgical personnel but also to the surgical patient, resulting in damage to the affected area during the operation. This reduces the burden on the patient by reducing the number of procedures and shortening the time, and for doctors who need skill and judgment, they can spend a lot of time on other surgical procedures, improving the surgical results. can get.

As described above, the drill bit with variable drilling direction according to the present invention is extremely useful for forming a bone hole in a surgical operation using an intramedullary nail, but other plastics, wood,
It can also be applied to drilling work on metal materials and the like.

[Brief description of drawings]

FIG. 1 is an enlarged side view of essential parts showing an example of a drilling direction variable drill blade according to the present invention.

FIG. 2 is an enlarged side view of an essential part when the drilling direction variable drill blade is slightly rotated.

FIG. 3 is an enlarged side view of essential parts when the drill bit with variable drilling direction is rotated by 90 °.

4A and 4B are views as seen from the distal end direction of the cross section of the drill with variable drilling direction in FIG. 3, in which FIG. 4A is a sectional view taken along line AA in FIG. 3 and FIG.
It is an inside BB sectional view.

FIG. 5 is a side view (a) showing a relationship between a bone and a drill blade at the time of aligning a drilling hole, and a schematic front view (b) of a monitor image of an image intensifier using an X-ray beam.

FIG. 6 is a side view (a) showing a relationship between a bone and a drill cutting edge at the start of drilling, and a schematic front view (b) of a monitoring image.

FIG. 7 is a side view (a) showing a relationship between a bone and a drill blade tip during drilling by a multidirectional drilling blade, and a schematic front view (b) of a monitoring image.

FIG. 8 is a side view (a) showing the relationship between the bone and the drill blade edge at the time of the original start of drilling by the drilling blade, and a schematic front view (b) of the monitoring image.
Is.

FIG. 9 is a side view (a) showing a relationship between a bone and a drill cutting edge when a drilling position is displaced, and a front schematic view (b) of a monitoring image.

FIG. 10 is a side view (a) showing a relationship between a bone and a drill blade when the drill axis O is inclined in the direction S of the center of the insertion hole, and a schematic front view (b) of a monitoring image.

FIG. 11 is a side view (a) showing the relationship between the bone and the drill cutting edge, showing a state in which the cutting edge has been moved to a target position, and a schematic front view (b) of a monitoring image.

FIG. 12 is a side view (a) showing a relationship between a bone and a drill blade when it is raised in an accurate drilling direction, and a schematic front view (b) of a monitoring image.

FIG. 13 is a cross-sectional view showing a state of fixing a bone treated by using an intramedullary nail.

FIG. 14 is a schematic side view (a) showing a conventional drilling operation using a jig, and schematic plan views (b) (c) showing a positional relationship between an arm of the jig and an intramedullary nail.

FIG. 15 is a schematic view showing a state of a drilling work using a radiolucent drill.

FIG. 16 shows a state in which an insertion hole is provided after the intramedullary nail is placed in the conventional bone marrow (a) when the drill is addressed, (b)
FIG. 4C is a sectional view at the start of perforation and FIG.

[Explanation of symbols]

1 punching blade 2 Perforation position holding blade 3 Multi-direction drilling blade 4 blade d Maximum base diameter of multi-directional drilling blade D Drilling diameter of drilling blade H Full rising height from punching blade Center of S insertion hole O drill axis 10 bones 10a fracture 11 intramedullary nail 12 Set screw 13 insertion hole 14 drill blade

Claims (5)

[Claims] 1. A variable drilling direction blade comprising a multidirectional drilling blade having a small drilling diameter and a flat cross section at the tip of the drilling blade, and a drilling position holding blade at the tip of the multidirectional drilling blade. 2. The variable drilling direction blade according to claim 1, wherein the multidirectional drilling blade has a maximum base diameter of 1/4 to 9/10 of the drilling diameter of the drilling blade. 3. The variable drilling direction blade according to claim 1, wherein the multidirectional drilling blade has a cross section of a substantially square shape or a substantially square shape provided with concave grooves or ridges. 4. The drilling direction variable drill blade according to claim 1, wherein the drilling position holding blade is formed in a cone shape having a sharp polygonal cross section having a substantially polygonal cross section having a smaller diameter toward the tip. 5. The punching position holding blade has a tip angle of 50 °.
The drilling direction variable drill blade according to claim 1 or 4, wherein the drill bit has a drilling angle of up to 90 °.