JP2009160278A - Medical cutting tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a medical cutting tool, which can recover chips produced by the cutting action, thereby enabling a hole to be made for inserting an implant stably therethrough. <P>SOLUTION: This medical cutting tool is provided with a supporting member 1 and a cutting member 2. The cutting member 2 has a cutting portion 21 formed at one end portion of a cylindrical body portion 20, and the cutting portion 21 has cutting edges 23 extended radially from the center axis of the body portion 20 toward the outer circumference. A center tip portion 24 is provided consecutively from the central portion, in which the cutting edges 23 are formed, and outer circumference tip portions 25 are formed at the outer circumference end portion. Between the cutting edges 23, inclined side faces 23b and side faces 23a of the adjoining cutting edges 23 are formed to intersect in valley shapes, in which inlet portions 26 are so individually formed in the valley-shaped portions as to communicate with the inside of the body portion 20. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a medical cutting tool used for drilling an insertion hole for an implant in a bone in a surgical operation such as dentistry, oral surgery, and orthopedic surgery.

  In surgical operations such as dentistry, oral surgery, and orthopedic surgery, it is necessary to accurately insert implants such as artificial roots, artificial joints, artificial bones, and fracture treatment tools. A hole is formed, and the implant is inserted into the insertion hole to be positioned and fixed.

As a medical cutting tool used for such drilling, for example, Patent Document 1 discloses a cutting blade that penetrates and forms a discharge path for cutting powder generated by a cutting operation in the axial direction and has an outermost peripheral portion in the rotational direction as an advance angle. A medical hollow drill is described in which a plurality of sheets are formed radially at regular intervals, and a cutting powder guide surface is formed in the discharge path direction from the outermost peripheral portion of the cutting blade. Further, Patent Document 2 discloses a first drill which is a molded drill having a function of creating an accurate cylindrical flat bottom hole while leaving a further cortical bone at the bottom of the maxillary sinus, and a disc shape with the maxillary sinus mucosa attached to the bottom of the hole sinus. A second drill, which is an incision drill having a function of separating cortical bone, and a lifting drill having a function of pushing the maxillary sinus mucosa together with the discoid cortical bone in contact with the discoid cortical bone at the base of the maxillary sinus A drilling device that uses a third drill in combination is described. Patent Document 3 describes a drill for drilling composed of a leading edge portion and a trailing edge portion of 2 to 4 blades on a spiral.
Japanese Utility Model Publication No. 5-42810 Japanese Patent No. 3706638 JP-A-6-304187

  In the case of a drill as described in Patent Documents 2 and 3, since the crushed material of the human bone generated by cutting is removed and discarded, it is difficult to reuse the crushed material. Although it is conceivable to collect the crushed material that has flowed out during cutting, there is a possibility that impurities may be mixed in when it flows out, which is not preferable.

  In Patent Document 1, the cutting powder generated by cutting is guided to the discharge path as it is, so that the cutting powder does not scatter around, but cutting is performed with the outermost peripheral portion in the rotation direction as the advance angle. It is difficult to cut efficiently because of the movement. In addition, the implant inserted with the bottom of the drilled hole having a raised shape in the center tends to be unstable.

  The shape of the bottom of such a drilled hole is preferably as close as possible to the shape of the implant. However, in the case of the drill shape described in Patent Document 1, the peripheral portion of the bottom becomes deep, so that the implant can be inserted to a predetermined depth. Must cut the peripheral part deeper than the depth, and will cut extra bone. Accordingly, damage to the living bone is increased correspondingly, and bone regeneration is delayed. In the case of the drill shape described in Patent Document 3, since the central portion is cut deeply, there is a problem that the living bone has to be cut similarly.

  Then, this invention aims at providing the medical cutting tool which can collect | recover the cut material which generate | occur | produces by cutting operation, and can form the hole part which can insert an implant stably. It is.

  The medical cutting tool according to the present invention is a medical cutting tool that performs a cutting operation by providing a cutting portion at one end of a tubular main body portion and rotating around a central axis of the main body portion. The cutting portion includes a plurality of cutting blade portions that extend radially from the central axis toward the outer periphery and are continuously provided on the center side so as to cover an end opening of the main body portion; and the cutting blade portion A central apex that protrudes outward along the central axis at a central portion of the main body, and a plurality of inlets that are formed between the cutting blades to introduce a cut material into the main body. It is characterized by. Furthermore, an outer peripheral pointed portion protruding in the direction of the central axis is formed on the outer peripheral side of the cutting blade portion. Furthermore, the cutting blade portion is characterized in that a cutting edge is formed by intersecting one side surface along the central axis and the other side surface inclined with respect to the central axis. Furthermore, an extraction member for taking out the cut material introduced from the introduction port portion is mounted inside the main body portion.

  By having the configuration as described above, a plurality of cutting blade portions are formed radially so as to cover one end opening of the tubular main body portion, and the central portions of the plurality of cutting blade portions are connected in series. A central point that protrudes outward along the center axis is formed, so if the main body is rotated around the central axis, multiple cutting blades extending radially around the central point will rotate. Thus, a stable cutting operation in the direction of the central axis can be performed.

  In addition, since a plurality of introduction ports for introducing the cut material into the tubular main body portion are formed between the plurality of cutting blade portions, the cut material cut by the cutting blade portion remains as it is in the main body portion. It will be housed inside. Therefore, the cut material accumulated in the main body after the cutting operation can be collected and reused, and the cut material can be reliably collected without flowing out.

  In addition, the cutting edge portion is formed with an outer peripheral tip that protrudes in the direction of the central axis on the outer peripheral side thereof, so that the center tip and the outer peripheral tip lead at the time of cutting operation, and the cutting operation is more stable. Is possible. Then, the center part and the outer peripheral part project and are cut so that the bottom surface of the hole to be drilled by the cutting operation is close to the shape of the implant, and if the cutting is performed until the center pointed part reaches a predetermined depth, the implant is inserted. Can drill to a wearable depth. For this reason, the living bone is not cut excessively, and damage to the living bone can be suppressed. Further, since the hole portion having a shape close to that of the implant can be finished, the gap between the inserted implant and the hole portion is reduced, and the regeneration of bone around the implant can be accelerated.

  Further, the cutting blade portion is formed so that the cutting blade portion covers the end opening because one side surface along the central axis and the other side surface inclined with respect to the central axis intersect to form the cutting edge. Even in this case, sufficient strength can be provided. A portion where one side surface of one cutting blade portion intersects the other side surface of the cutting blade portion adjacent thereto is formed in a valley shape, and an introduction port portion is formed in the valley shape portion. Thus, the cut body of living bone is smoothly introduced into the introduction port as the main body rotates, and the cut material can be reliably collected in accordance with the rotation of the main body.

  In addition, by installing a take-out member for taking out the cut material introduced from the introduction port portion inside the tubular main body portion, it is possible to efficiently take out the cut material accumulated inside the main body portion with the cutting operation. it can.

  Hereinafter, embodiments according to the present invention will be described in detail. The embodiments described below are preferable specific examples for carrying out the present invention, and thus various technical limitations are made. However, the present invention is particularly limited in the following description. Unless otherwise specified, the present invention is not limited to these forms.

  FIG. 1 is an exploded perspective view of an embodiment according to the present invention. The medical cutting tool includes a support member 1 and a cutting member 2. The support member 1 has a flange portion 11 and a screw fixing portion 12 formed on one end side of a rod-shaped main body portion 10, and a locking portion 13 formed on the other end side. The cutting member 2 has a cutting portion 21 formed at one end of a cylindrical main body portion 20 and an attachment screw portion 22 formed at the other end.

  The attachment screw portion 22 has a thread groove formed on the inner peripheral surface of the main body portion 20, and is screwed to the screw fixing portion 12 of the support member 1. Then, the mounting screw portion 22 is screwed until it comes into contact with the flange portion 11, and the cutting member 2 is fixed to the support member 1.

  The locking portion 13 of the support member 1 is cut and formed so as to leave the end portion in a flange shape with a predetermined thickness, and is partially cut out along the central axis of the support member 1. The locking portion 13 is attached to a drive head (not shown), and the support member 1 is driven to rotate about its central axis by the drive head. The cutting members 2 are set so that their center axes coincide with each other in a state of being fixedly attached to the support member 1.

  2 is a side view of the cutting member 2 (FIG. 2A), a front view as viewed from the central axis direction (FIG. 2B), and an AA cross-sectional view (FIG. 2C). The cutting part 21 includes three cutting blade parts 23. Each cutting blade portion 23 extends radially from the central axis O of the main body portion 20 toward the outer periphery, and the center side of each cutting blade portion 23 is continuously provided to cover the end opening of the main body portion 20. Is formed.

  Each cutting blade portion 23 extends radially from the central axis O of the main body portion 20 toward the outer periphery, and extends radially from the side surface 23a formed along the central axis O and from the central axis O toward the outer periphery. The side 23b formed so as to be inclined with respect to the central axis intersects to form a blade edge 23c.

  A central apex 24 is formed at the central portion where the three cutting blades 23 are continuously provided so as to protrude outward along the central axis O. The central tip 24 is formed in a tapered shape that gathers so that the cutting edge 23c of the cutting blade 23 converges. Moreover, the outer peripheral side edge part of the three cutting blade parts 23 is formed with the outer peripheral pointed part 25 so that the cutting edge 23c protrudes outward in the direction of the central axis O, and the cutting edge 23c of each cutting blade part 23 is , Both ends are finished in a curved shape protruding outward. The center pointed portion 24 is set so as to protrude slightly outward from the outer peripheral pointed portion 25.

  Between each cutting blade part 23, the inclined side surface 23b and the side surface 23a of the adjacent cutting blade part 23 cross | intersect, and it is formed in the valley shape, and the introduction port part 26 is each in the part formed in the valley shape. It is formed so as to communicate with the inside of the main body 20.

  FIG. 3 is a perspective view showing a state in which the cutting member 2 is attached and fixed to the support member 1. By attaching the cutting member 2 to the support member 1 and rotating the support member 1 around the central axis, the cutting blade portion 23 rotates around the central apex 24 in the cutting portion 21, and the central apex 24 The cutting edge 23c of the cutting blade portion 23 extending radially from the rotation rotates to perform a cutting operation.

  FIG. 4 is an explanatory diagram regarding a cutting operation for punching a living bone. First, the meat part M covering the surface of the bone part B to be perforated is removed to expose the bone part B, and the central tip 24 and the outer peripheral tip 25 of the cutting part 21 are brought into contact with the exposed surface of the bone part B. . Then, a force is applied in the direction of the central axis so that the distal ends of the central apex portion 24 and the outer peripheral apex portion 25 are sunk into the bone portion B to position the cutting member 2 in a stable state (FIG. 4A).

  After positioning the cutting member 2 with respect to the bone portion B, the support member 1 is driven to rotate, and the cutting member 2 is rotated about the central axis. When a force is applied to the cutting member 2 in the direction of the central axis, the cutting edge 23c formed from the central apex 24 to the outer peripheral apex 25 rotates while sliding on the surface of the bone portion B to perform the cutting operation. It is. At that time, the center pointed portion 24 protrudes most outward and is always sunk into the bone portion B, so that a stable cutting operation is performed without causing a positional shift. In addition, since the cutting edge 23c rotates and the cutting operation is performed while the outer peripheral tip 25 protrudes outward, the cutting portion 21 can be accurately drilled in the direction of the central axis without shaking.

  Then, the bone cut material G crushed by the cutting blade portion 23 is guided to a valley-like portion between the cutting blade portions 23 and introduced into the main body portion 20 from the introduction port portion 26. At this time, the crushed cut material G is directly introduced into the main body 20 immediately after being cut, so that it can be recovered without being mixed with impurities (FIG. 4B).

  When the cutting member 2 is pulled up after performing a cutting operation to a predetermined depth, a circular hole H having substantially the same diameter as the cutting member 2 is drilled (FIG. 4C). The bottom surface of the hole H is formed in a planar shape perpendicular to the central axis of the cutting member 2 although there are slight depressions due to the central pointed portion 24 and the outer peripheral pointed portion 25 of the cutting portion 21. Therefore, as shown in FIG. 4D, when the implant I is inserted into the hole H, the gap between the two becomes small, and the implant I can be positioned in a stable state. In addition, since the gap between the implant I and the bone part B is small, healing by bone regeneration is performed at an early stage. Since only a portion necessary for insertion of the implant can be drilled by a cutting operation, damage to the living bone can be minimized.

  In the example described above, three cutting blade portions are provided, but a plurality of cutting blade portions may be formed and the number is not limited to three. Moreover, the shape of the cutting blade part should just be a shape in which the valley-shaped part was formed between adjacent cutting blade parts, and what is necessary is just to change the shape of the cutting blade part mentioned above as needed.

  FIG. 5 is a perspective view showing a modification in which a support member 1 is provided with an extraction member for taking out the cut material collected in the main body 20 of the cutting member 2. In the example shown in FIG. 5A, the extraction member 3 is attached and fixed to the center portion of the screw fixing portion 12. Further, in another example shown in FIG. 5B, the extraction member 4 is attached and fixed to the center portion of the screw fixing portion 12.

  In the take-out member 3, a spiral groove 30 a is formed on the outer periphery of a cylindrical main body 30 having a diameter slightly smaller than the inner peripheral surface of the cutting member 2. The surface of the tip 31 of the main body 30 is formed in a conical shape so as to match the inner surface of the cutting part 21 of the cutting member 2. The spiral groove 30a is formed up to the surface of the tip portion 31. When the tip portion 31 comes into contact with the inner surface of the cutting portion 21, the groove 30a faces the introduction port portion 26 of the cutting portion 21. Is set.

  FIG. 6 is an explanatory diagram when the cutting member 2 is attached to the support member 1 shown in FIG. The cutting operation is similar to the operation described in FIG. When the cutting member 2 is attached to the support member 1 to which the extraction member 3 is fixed, the outer peripheral surface of the main body 30 of the extraction member 3 comes into contact with the inner peripheral surface of the cutting member 2 with almost no gap. The surface of the tip portion 31 is also in close contact with the inner surface of the cutting portion 21 (FIG. 6A).

  Then, when the cutting operation is performed by rotating the support member 1, the cut material is collected into the cutting member 2 from the introduction port portion 26, but the collected cut material G is guided to the groove 30 a. (FIG. 6B). Therefore, as the cutting operation proceeds, the cut object is sequentially pushed into the spiral groove 30a and accumulated.

  When the cutting member 2 is removed from the support member 1 after the cutting operation is finished, the cut object G accumulated in the groove 30a remains as it is, and the cut object G can be taken out cleanly from the inside of the cutting member 2 (FIG. 6C). )).

  In the take-out member 4 shown in FIG. 5 (b), a disk-shaped main body 41 is fixed to the distal end portion of an elongated rod-shaped attachment portion 40. The attachment portion 40 is erected along the central axis at the central portion of the screw fixing portion 12. The main body 41 is formed to have a diameter slightly smaller than the inner peripheral surface of the cutting member 2, and the tip of the attachment portion 40 is fixed to the center of the bottom surface. The surface of the front end portion 42 of the main body 41 is formed in a conical shape so as to match the inner surface of the cutting portion 21 of the cutting member 2. The main body 41 is provided with a plurality of communication holes 43 so as to penetrate the tip portion 42 and the bottom surface.

  FIG. 7 is an explanatory diagram when the cutting member 2 is attached to the support member 1 shown in FIG. The cutting operation is similar to the operation described in FIG. When the cutting member 2 is attached to the support member 1 to which the extraction member 4 is fixed, the outer peripheral surface of the main body 41 of the extraction member 4 comes into contact with the inner peripheral surface of the cutting member 2 with almost no gap. The surface of the front end portion 42 is also in close contact with the inner surface of the cutting portion 21 (FIG. 6A). And in the state which attached the cutting member 2 to the supporting member 1, the communicating hole 43 formed in the main-body part 41 will be positioned in the position facing the inlet 26 of the cutting part 21, and will be in the state which both communicated. .

  When the support member 1 is rotated to perform a cutting operation, the cut material is guided to the introduction port portion 26 and is collected into the cutting member 2 through the communication hole 43 (FIG. 7B). ). Therefore, the cutting object G is accumulated above the main body 41 as the cutting operation proceeds.

  When the cutting member 2 is removed from the support member 1 after the cutting operation is finished, the cutting object G accumulated above the main body 41 is pulled up as it is, and the cutting object G can be taken out from the inside of the cutting member 2 cleanly (see FIG. 7 (c)).

  The medical cutting tool according to the present invention can be suitably used for drilling an insertion hole for an implant in a bone in a surgical operation such as dentistry, oral surgery, and orthopedic surgery. It is possible to collect and reuse the cut material such as the crushed material without throwing it away. In addition, since the cut material can be efficiently collected, even when used as a cutting tool when processing a noble metal material, it is possible to collect and reuse all the cut material.

It is a disassembled perspective view regarding embodiment which concerns on this invention. It is the side view regarding a cutting member, the front view seen from the central-axis direction, and AA sectional drawing. It is a perspective view which shows the state which attached and fixed the cutting member to the support member. It is explanatory drawing regarding the cutting operation for punching a living bone. It is a perspective view of the supporting member regarding a modification. It is explanatory drawing regarding cutting operation of a modification. It is explanatory drawing regarding cutting operation | movement of another modification.

Explanation of symbols

1 Support member
10 Body 2 Cutting material
20 Main unit
21 Cutting part
23 Cutting blade
24 Center apex
25 Perimeter tip
26 Inlet 3 Extraction member
30 Main unit
30a Groove 4 Extraction member
41 Main unit
43 Communication hole

Claims (4)

  A medical cutting tool that is provided with a cutting portion at one end of a tubular main body portion and performs a cutting operation by rotating around a central axis of the main body portion, and the cutting portion is arranged on the outer periphery from the central axis. A plurality of cutting blade portions that are radially extended toward the center side and are formed so as to cover the end opening of the main body portion along the central side, and the central portion of the cutting blade portion along the central axis A medical cutting characterized by comprising a center pointed end projecting outward and a plurality of introduction ports formed between the cutting blades to introduce a cut material into the main body. Ingredients.   The medical cutting tool according to claim 1, wherein an outer peripheral pointed portion protruding in the direction of the central axis is formed on an outer peripheral side of the cutting blade portion.   The medical blade according to claim 1 or 2, wherein the cutting blade portion has a blade edge formed by intersecting one side surface along the central axis and the other side surface inclined with respect to the central axis. Cutting tool.   The medical cutting tool according to any one of claims 1 to 3, wherein an extraction member for taking out a cut material introduced from the introduction port portion is mounted inside the main body portion.

Images