JP2010131298A - Bone cutting reamer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bone cutting reamer, smoothing the rotation of the bone cutting reamer. <P>SOLUTION: This bone cutting reamer 1 includes: a blade part 2; a shaft part 3 provided with the blade part 2 at the tip thereof; and a cylindrical sleeve 4 rotatably fitted to the shaft part 3. In this configuration, since the shaft part is rotatable in relation to the sleeve, the rotation of the shaft part is not obstructed even if the sleeve abuts on a guide member in the rotating state of the blade part. Further, since the sleeve is cylindrical, the rotation of the sleeve is not restrained by the guide member abutting on the outer peripheral surface of the sleeve. Thus, the rotation of the bone cutting reamer can be smoothed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a bone cutting reamer for cutting bone using a guide member.

Conventionally, as a bone cutting reamer for cutting bone using a guide member, a rotary reamer described in Patent Document 1 is known.
As described in FIG. 1 of Patent Document 1, the rotary reamer (22) was provided at a cutting end (25), a reamer contact (23), a shaft, and a base end of the shaft. The drive device connecting portion (24) is integrally formed. Then, the bone is cut by inserting and rotating the rotary reamer (22) into the opening (21A) of the collet (21) as the guide member.

Special Table 2000-505337

  However, the rotary reamer described in Patent Document 1 slides on the guide member, and thus both the rotary reamer and the guide, or any one of the tools, is damaged, and the rotary reamer cannot be smoothly rotated. There is a fear. In this case, accurate bone cutting becomes difficult.

  In view of the above circumstances, an object of the present invention is to provide a bone cutting reamer capable of smoothly rotating a bone cutting reamer.

  In order to achieve the above object, the bone cutting reamer according to the present invention has several features as follows. In other words, the bone cutting reamer of the present invention has the following features alone or in combination.

  In order to achieve the above object, the first feature of the bone cutting reamer according to the present invention is that a blade portion, a shaft portion provided at the tip of the blade portion, and a pivotally attached to the shaft portion. And a cylindrical sleeve.

According to this configuration, since the shaft portion is rotatable with respect to the sleeve, even if the sleeve abuts against the guide member when the blade portion is rotated, the rotation of the shaft portion is not hindered.
Furthermore, since the sleeve is cylindrical, the rotation of the sleeve is not restricted by the guide member that contacts the outer peripheral surface of the sleeve.
As a result, the bone cutting reamer can be smoothly rotated.

  A second feature of the bone cutting reamer according to the present invention is that the sleeve is made of resin.

  According to this configuration, the sliding between the sleeve and the shaft portion and the sliding between the sleeve and the guide member are smoothly performed. Thereby, rotation of a blade part becomes smooth.

  The third feature of the bone cutting reamer according to the present invention is that a lock member fixed to the shaft portion is constrained so as to restrain movement of the sleeve in a direction away from the blade portion, and a flange is attached to the sleeve. Part is provided.

  According to this configuration, since the flange portion can be brought into contact with the guide member, the depth cut by the blade portion can be prevented from becoming excessively deep.

  The fourth feature of the bone cutting reamer according to the present invention is that the position of the lock member in the axial direction can be adjusted.

  According to this structure, the depth cut by the blade portion can be adjusted to a predetermined depth by adjusting the position of the lock member.

  The fifth feature of the bone cutting reamer according to the present invention is that the shaft portion has a convex portion that restrains the movement of the sleeve in a direction approaching the blade portion.

  According to this structure, it can prevent that a sleeve moves and contacts a blade part. Thereby, damage to the sleeve can be prevented.

  Even if the sleeve comes into contact with the guide member, the rotation of the shaft portion is not hindered, and the rotation of the sleeve is difficult to be restrained by the guide member that comes into contact with the outer peripheral surface of the sleeve. Can be done smoothly.

Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.
In the present embodiment, a reamer used for excising the bone at the central part of the intercondylar part in the distal part of the femur will be described as an example.

(First embodiment)
<Overall configuration of bone cutting reamer>
FIG. 1 is an overall perspective view showing a bone cutting reamer 1 according to a first embodiment of the present invention.
FIG. 2 is an exploded perspective view of the bone cutting reamer 1 shown in FIG.
FIG. 3 is an enlarged cross-sectional view of the vicinity of the sleeve 4 in the bone cutting reamer 1 shown in FIG.

  As shown in FIGS. 1 and 2, a bone cutting reamer 1 includes a blade portion 2 on which a blade for cutting bone is formed, a shaft portion 3 provided with the blade portion 2 at the tip, and a shaft portion 3. And a lock member 5 provided on the shaft portion 3 so as to restrain the movement of the sleeve 4.

<Configuration of blade and shaft>
The blade portion 2 and the shaft portion 3 are formed of a stainless alloy that is a metal that can be sterilized as a medical instrument material. In addition, you may use not only a stainless alloy but the other metal which can be sterilized as a medical instrument material. For example, a titanium alloy may be used. Moreover, the axial part 3 may be formed with resin which can be sterilized not only as a metal but as a medical instrument material. For example, fluororesin (PTFE), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), polyacetal (POM), or the like can be used.

  As shown in FIG. 2, the shaft portion 3 includes a cylindrical tip shaft portion 31 continuous from the blade portion 2, an intermediate shaft portion 32 provided with the lock member 5 continuously from the tip shaft portion 31, and an intermediate shaft portion. A proximal end shaft portion 33 extending continuously from the blade portion 2 in a direction away from the blade portion 2, and a rotation means connecting portion 34 provided at an end portion of the proximal end shaft portion 33.

  The tip shaft portion 31 is provided with a convex portion 31 a protruding from the outer periphery at a position close to the blade portion 2. The convex portion 31 a is continuous over the entire circumference of the distal end shaft portion 31.

The intermediate shaft portion 32 is formed with a pair of planes that are parallel to each other on the outer periphery. Grooves 32a extending in the direction perpendicular to the central axis direction of the shaft portion 3 (hereinafter referred to as “axial direction”) are formed in the pair of planes.
The intermediate shaft portion 32 is formed so as to be located inside the outer peripheral edge of the distal end shaft portion 31 when viewed from the axial direction.

  The proximal end shaft portion 33 is smaller in diameter than the distal end shaft portion 31 and is formed so as to be located inside the outer peripheral edge of the intermediate shaft portion 32 when viewed in the axial direction.

  The rotation means connecting portion 34 is formed so as to be able to engage with rotation means such as a motor driving device (not shown) in the rotation direction and the axial direction.

<Configuration of sleeve>
The sleeve 4 is formed in a cylindrical shape from a resin that can be sterilized as a medical device material.
As a material for the sleeve 4, it is desirable to use a resin that has a small coefficient of friction with the shaft portion 3. For example, fluorine resin (PTFE), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), polyacetal (POM), or the like can be used.

As shown in FIG. 2, the sleeve 4 includes a cylindrical body portion 41 and a flange portion 42 that is provided at an end portion of the body portion 41 and protrudes radially outward.
The trunk portion 41 is formed so that the inner diameter is larger than the outer diameter of the tip shaft portion 31 of the shaft portion 3 and smaller than the outer diameter of the convex portion 31a. As shown in FIG. 3, a step portion 41 a is formed at the distal end of the inner periphery of the body portion 41 so that the inner periphery has a larger diameter than the proximal end side.
The flange portion 42 is continuous over the entire circumference of the distal end shaft portion 31 and is formed so that the outer diameter is larger than the inner diameter of a cylindrical guide 12 described later.

The sleeve 4 is inserted into the distal end shaft portion 31 of the shaft portion 3 and can rotate around the axis of the distal end shaft portion 31.
Further, as shown in FIG. 3, the movement of the sleeve 4 toward the blade part 2 side is regulated by the surface of the step part 41a facing the tip side coming into contact with the convex part 31a, and the movement toward the intermediate shaft part 32 side. Is regulated by contacting the lock member 5. That is, the sleeve 4 is movable in the axial direction between the convex portion 31 a of the shaft portion 3 and the lock member 5.

<Configuration of lock member>
The lock member 5 is formed of the same material as the blade portion 2 and the shaft portion 3, and has a hollow inner ring-shaped member 51, a locking member 52 inserted into the ring-shaped member 51, and the ring-shaped member 51. And a spring 53 provided between the locking member 52 and the locking member 52. The lock member 5 is not limited to the same material as that of the blade portion 2 and the shaft portion 3, and other metal or resin that can be sterilized as a medical instrument material may be used.

The ring-shaped member 51 is an internal hollow member in which both ends in the axial direction of the cylindrical portion are closed by the disk-shaped portion. A first opening 51 a having substantially the same shape as the axial vertical cross-sectional shape of the intermediate shaft portion 32 is provided at the center of the disk-shaped portion. A second opening 51 b that communicates with the internal space is formed on the outer peripheral surface of the cylindrical portion of the ring-shaped member 51.
The locking member 52 is inserted into the ring-shaped member 51 from the second opening 51 b of the ring-shaped member 51.
The spring 53 urges the locking member 52 to push it outward from the second opening 51b.
The locking member 52 is formed with a through hole 52a into which the intermediate shaft portion 32 can be inserted in a direction perpendicular to the direction of insertion into the ring-shaped member 51 from the second opening 51b. On the inner peripheral surface of the through-hole 52a, an engagement convex portion 52b that protrudes in the same direction as the biasing direction of the spring 53 is provided.

  When the locking member 52 is pushed into the ring-shaped member 51 against the urging force of the spring 53, the engagement convex portion 52b of the locking member 52 inserts the intermediate shaft portion 32 into the through hole 52a. Move to an unobstructed position. In this state, when the intermediate shaft portion 32 is inserted into the first opening 51a and the through hole 52a and the pressing to the locking member 52 is released in the inserted state, the engagement is caused by the biasing force of the spring 53. The convex portion 52 b engages with the groove 32 a of the intermediate shaft portion 32. Thereby, the movement of the lock member 5 in the axial direction is restricted.

  In the first embodiment, the first opening 51a of the lock member 5 has a shape that engages with the intermediate shaft 32 inserted in the first opening 51a in the rotation direction, so that the shaft 3 rotates. The lock member 5 also rotates. Thereby, sliding with the lock member 5 and the axial part 3 becomes difficult to occur, and generation | occurrence | production of abrasion powder between the locking member 5 and the axial part 3 is suppressed.

<Cutting method>
Next, a method of excising the bone at the central part of the intercondylar part in the distal part of the femur using the bone cutting reamer 1 will be described.
FIG. 4 is a perspective view for explaining a cutting method by the bone cutting reamer 1.
FIG. 5 is a perspective view showing a state in which the bone cutting reamer 1 is inserted into the cylindrical guide 12.
6 is a cross-sectional view of the femur 100, the guide member 10, and the bone cutting reamer 1 shown in FIG.
FIG. 7 is a cross-sectional view showing a state in which the femur 100 is cut with the bone cutting reamer 1.

As shown in FIG. 4, a guide member 10 that guides the bone cutting reamer 1 so that the center of the intercondylar part of the femur 100 is cut at the distal end of the femur 100 to be cut. Fixed.
The guide member 10 includes a guide main body 11 formed in a substantially U shape in a side view and a cylindrical guide 12 fixed to the outer surface of the guide main body 11.

  The guide body 11 is fitted into a distal portion of the femur 100 whose outer surface is cut into a predetermined shape, and is fixed to the femur 100 with bolts or pins 13 or the like. The guide body 11 has an opening at a position corresponding to the intercondylar portion so that only the center of the intercondylar portion of the femur 100 is exposed.

The cylindrical guide 12 is formed so that the inner diameter is larger than the outer diameter of the body portion 41 of the sleeve 4 and smaller than the outer diameter of the flange portion 42. The cylindrical guide 12 is provided such that its cylindrical central axis is substantially perpendicular to the end surface 100a of the femur 100, and is slidable to the front surface 100b side and the rear surface 100c side of the femur 100 in parallel with the end surface 100a. Yes (see FIG. 6).
The cylindrical guide 12 slides within a predetermined range in which the blade portion 2 of the bone cutting reamer 1 inserted into the cylindrical guide 12 can reach the femur 100 through the opening of the guide body 11. Is possible.

After the guide member 10 is attached to the femur 100, the bone cutting reamer 1 is inserted into the cylindrical guide 12 as shown in FIGS. 5 and 6.
Note that the length of the sleeve 4 and the position of the lock member 5 in the axial direction are such that the tip of the sleeve 4 is inserted into the cylindrical guide 12 before the tip of the blade portion 2 contacts the end face of the femur 100. Is set.

With the distal end of the sleeve 4 inserted into the cylindrical guide 12, the shaft portion 3 of the bone cutting reamer 1 is rotated by a rotating means (not shown). At this time, relative rotation occurs between the outer peripheral surface of the shaft portion 3 and the inner peripheral surface of the sleeve 4 and / or between the outer peripheral surface of the sleeve 4 and the inner peripheral surface of the cylindrical guide 12. Thereby, rotation of blade part 2 is performed smoothly.
And the femur 100 is cut by advancing the blade part 2 toward the femur 100.

  As shown in FIG. 7, when the bone cutting reamer 1 moves a predetermined amount toward the femur 100, the end portion of the cylindrical guide 12 comes into contact with the flange portion 42. Since the movement of the sleeve 4 is restricted to the proximal end side of the shaft portion 3 by the lock member 5, the bone cutting reamer 1 cannot be further moved to the femur 100 side. Thereby, it is prevented that the cutting depth of the femur 100 by the blade part 2 becomes deeper than a predetermined depth.

  Further, since the blade portion 2 of the bone cutting reamer 1 is also formed on the outer peripheral surface, the cylindrical guide 12 and the bone cutting reamer 1 are moved with respect to the guide main body 11 while the blade portion 2 is rotated. By sliding, cutting can be advanced also in the axial direction. At this time, since the radial load is received by the sleeve 4, the blade portion 2 can rotate smoothly.

<Effects of First Embodiment>
As described above, the bone cutting reamer 1 according to the first embodiment is attached to the blade portion 2, the shaft portion 3 provided with the blade portion 2 at the tip, and the shaft portion 3 so as to be rotatable. A cylindrical sleeve 4.

  According to this configuration, since the shaft portion 3 can rotate with respect to the sleeve 4, even when the blade portion 2 rotates, even if the sleeve 4 abuts on the cylindrical guide 12, the shaft portion 3 is prevented from rotating. It will never be done. Thereby, rotation of the bone cutting reamer 1 can be performed smoothly.

Further, since the relative rotation is possible between the sleeve 4 and the cylindrical guide 12, the rotation of the bone cutting reamer 1 becomes smoother.
Since the sleeve 4 is formed in a cylindrical shape, not only when the cylindrical cylindrical guide 12 is used as a guide member, but also when a rectangular guide frame or the like is used, the sleeve 4 in contact with the guide member. Is rotatable relative to the guide member. Thereby, rotation of the bone cutting reamer 1 can be made smooth.

  Thus, since relative rotation can occur between the inner peripheral surface of the sleeve 4 and the outer peripheral surface of the shaft portion 3 and between the outer peripheral surface of the sleeve 4 and the inner peripheral surface of the cylindrical guide 12, for example, Even if one of the relative rotations is stopped due to foreign matter or the like, the rotation of the blade portion 2 is not hindered unless the other relative rotation is stopped.

  Further, since the sleeve 4 is made of resin, sliding between the resin sleeve 4 and the metallic shaft portion 3 and between the resin sleeve 4 and the metallic cylindrical guide 12 are performed. Sliding between them is performed smoothly. Thereby, rotation of the blade part 2 becomes smooth. Further, it is possible to suppress the generation of wear powder due to the friction between the sleeve 4 and the shaft portion 3 and the friction between the sleeve 4 and the cylindrical guide 12.

  Further, the bone cutting reamer 1 includes a lock member 5 fixed to the shaft portion 3 so as to restrain the movement of the sleeve 4 in the direction away from the blade portion 2 (the axial base end side). A portion 42 is provided.

  According to this configuration, when the bone cutting reamer 1 is pushed into the femur 100 side, the flange portion 42 comes into contact with the cylindrical guide 12 and the movement of the bone cutting reamer 1 in the pushing direction is restricted. The depth cut by the blade portion 2 can be prevented from becoming excessively deep.

  Here, since the sleeve 4 is made of resin, sliding with the metal cylindrical guide 12 and sliding with the metal lock member 5 are performed smoothly, and wear powder It is hard to produce.

  Further, the shaft portion 3 has a convex portion 31a that restrains the movement of the sleeve 4 in the direction approaching the blade portion 2 (the front end side in the axial direction).

  According to this structure, it can prevent that the sleeve 4 moves and contacts the blade part 2. FIG. Thereby, damage to the sleeve 4 can be prevented.

  Further, since the sleeve 4 and the lock member 5 are attached to the shaft portion 3 without using screws, the sleeve 4 and the lock member 5 can be easily detached from the shaft portion 3. This facilitates cleaning of the bone cutting reamer 1.

  Further, the lock member 5 is configured without using screws, and can be disassembled into a ring-shaped member 51, a locking member 52, and a spring 53. Therefore, the lock member 5 can be easily cleaned.

(Second Embodiment)
Next, a bone cutting reamer according to a second embodiment of the present invention will be described.
FIG. 8 is a cross-sectional view showing a bone cutting reamer according to a second embodiment of the present invention.
The bone cutting reamer of the second embodiment is different from the first embodiment in the configuration of the intermediate shaft portion 32 in the shaft portion 3. The same members as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  In the intermediate shaft portion 132 of the second embodiment, a pair of planes that are parallel to each other are formed on the outer periphery, as in the first embodiment. Two grooves 132a and 132b extending in a direction perpendicular to the axial direction are formed on the pair of planes. The two grooves 132a and 132b are formed so that the locking member 52 can be engaged, and are arranged at a predetermined interval in the axial direction.

  According to this configuration, the locking member 52 can be engaged with the groove 132a or can be engaged with the groove 132b. Thereby, the attachment position of the lock member 5 can be changed in an axial direction.

  That is, compared with the case where the locking member 52 is engaged with the groove 132a formed at a position close to the blade portion 2 (see FIG. 8A), it is formed at a position farther from the blade portion 2 than the groove 132a. When the locking member 52 is engaged with the groove 132b formed (see FIG. 8B), the depth that can be cut with the bone cutting reamer is deeper.

  As described above, since the bone cutting reamer of the second embodiment can adjust the position of the lock member 5 in the axial direction, the depth of cutting by the blade portion 2 is adjusted to a predetermined depth according to the situation. Can do.

  Further, since the position of the lock member 5 in the axial direction can be easily adjusted simply by urging the locking member 52 against the spring 53, the position can be adjusted quickly.

(Modification)
Next, a modification of the above embodiment will be described.
FIG. 9 shows a modification of the bone cutting reamer 1 according to the first embodiment.
In this modification, the structure of the locking member 54 in the lock member 5 is different from the locking member 52 (see FIG. 3) of the first embodiment.
The locking member 54 of the modified example is formed with a pin insertion hole 54c penetrating in the axial direction on the opposite side to the engaging convex portion 54b with the shaft portion 3 interposed therebetween. And the pin 55 provided penetrating the ring-shaped member 51 is inserted in the pin insertion hole 54c.
The pin insertion hole 54c is formed so that the locking member 54 can move in the biasing direction by the spring 53 even when the pin 55 is inserted. The locking member 54 is movable in a range wider than at least the width corresponding to the protruding length of the engaging convex portion 54b.
Therefore, by urging the locking member 54 against the urging force of the spring 53, the engagement of the engagement convex portion 54b with the shaft portion 3 can be released.
Further, according to this configuration, the locking member 54 is not detached from the ring-shaped member 51 unless the pin 55 is removed. Therefore, it is possible to prevent the lock member 5 from being unintentionally disassembled.

  The configuration is not limited to the case where the pin 55 is used, and a bolt may be screwed into the ring-shaped member 51 and the shaft of the bolt may be inserted into the pin insertion hole 54c.

  As shown in FIG. 10, similarly, in the bone cutting reamer according to the second embodiment, the locking member 54 formed with the pin insertion hole 54 c is used, and the locking member 54 is removed by the pin 55. It is also possible to prevent.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims.

The whole perspective view which shows the reamer for bone cutting which concerns on 1st Embodiment of this invention. The disassembled perspective view of the reamer for bone cutting shown in FIG. The cross-sectional enlarged view of the sleeve vicinity in the reamer for bone cutting shown in FIG. The perspective view for demonstrating the cutting method by the reamer for bone cutting. The perspective view which shows the state which inserted the reamer for bone cutting in the cylindrical guide. FIG. 6 is a cross-sectional view of the femur, guide member, and bone cutting reamer shown in FIG. 5. Sectional drawing which shows the state which cut the femur with the reamer for bone cutting. (A) The cross-sectional enlarged view of the reamer for bone cutting which concerns on 2nd Embodiment of this invention, and (b) The cross-sectional enlarged view which shows the state which changed the position of the locking member. The figure which shows the modification of the reamer for bone cutting of 1st Embodiment. The figure which shows the modification of the reamer for bone cutting of 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bone cutting reamer 2 Blade part 3 Shaft part 31a Convex part 4 Sleeve 42 Flange part 5 Lock member

Claims (5)

A blade,
A shaft portion provided at the tip of the blade portion;
A cylindrical sleeve rotatably attached to the shaft portion;
Bone cutting reamer with   The bone cutting reamer according to claim 1, wherein the sleeve is made of resin. A lock member fixed to the shaft portion so as to restrain movement of the sleeve in a direction away from the blade portion;
The bone cutting reamer according to claim 1 or 2, wherein a flange portion is provided on the sleeve.   The bone cutting reamer according to claim 3, wherein the position of the lock member in the axial direction can be adjusted.   The bone cutting reamer according to any one of claims 1 to 4, wherein the shaft portion includes a convex portion that restrains the movement of the sleeve in a direction approaching the blade portion.

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