JP6684411B1 - Bone cutting instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bone resection tool capable of easily and highly accurately performing additional resection on a resection surface of a bone. A bone cutting instrument (1) has a tip saw blade (12) and vibrates at a high speed to cut a bone with which the tip saw blade (12) contacts, and a substantially flat blade body (10) and a substantially flat tip guide. A guide plate 20 that has a portion 21 and is located on the upper surface side of the blade body 10 and is slidably connected to the blade body 10 in the front-rear direction. A projecting guide position that projects toward the tip side of the saw blade 12 and covers the tip saw blade 12, guides the cutting position in the thickness direction by the tip saw blade 12, and a retracted position where the tip guide part 21 retracts from the tip saw blade 12. And a guide plate 20 that is slidable between and. [Selection diagram] Figure 1

Description

  The present invention relates to a bone cutting instrument for cutting a part of bone.

  Conventionally, artificial knee joint replacement surgery has been widely performed as a treatment method for osteoarthritis of the knee. In the total knee arthroplasty, it is necessary to excise the bone replacement part and fix the artificial knee joint to the excised surface. Here, as a bone resection tool for resecting bone, for example, a blade for bone cutting disclosed in Patent Documents 1 and 2 below is provided.

Special table 2007-532253 gazette Special table 2016-5299952 gazette

  By the way, in artificial knee joint replacement surgery, high joint accuracy between the bone and the artificial knee joint is required, and in some cases, additional resection in 1 mm increments is required for the resection surface where the bone has been once excised by cutting or the like. Many.

  Conventionally, additional resection of small-sized bone was performed using the bone cutting blade as it is or using a chisel or file, but it is extremely advanced to perform additional resection with an accurate size. A great deal of skill is required, which puts a heavy burden on the doctor.

  The present invention has been made in view of the above problems, and an object thereof is to provide a bone resection tool that can easily and highly accurately perform additional resection on a resection surface of a bone.

  In order to solve the above problems, the bone cutting instrument according to the present invention is a bone cutting instrument for cutting bone, having a tip saw blade, and by vibrating at high speed, the bone the tip saw blade contacts. A blade body having a substantially flat plate shape for cutting, and a guide having a substantially flat plate-shaped tip guide portion, which is located on the upper surface side of the blade body and is slidably coupled to the blade body in the front-rear direction. In the plate, the tip guide portion projects toward the tip side from the tip saw blade of the blade body to cover the tip saw blade, and a protruding guide position that guides the cutting position in the thickness direction by the tip saw blade, A guide plate slidable between the tip guide portion and a retracted position retracted from the saw blade.

  Further, the guide plate according to the present invention has a tip saw blade, and by vibrating at high speed, a guide plate used by being attached to a substantially flat blade body that cuts the bone with which the tip saw blade contacts. In the above, a substantially flat plate-shaped tip guide portion and a slide rail portion that clamps the blade body from the upper surface side are provided, and the tip guide portion projects toward the tip side from the tip saw blade of the blade body and the tip. Between the protruding guide position that covers the saw blade and guides the cutting position in the thickness direction by the tip saw blade, and the retracted position where the tip guide part retracts from the tip saw blade, the blade body and the front-rear direction are relative to each other. Is slidably connected to the tip guide portion, and the tip guide portion moves upward when the tip guide portion is located at the protruding guide position. Wherein the opening window for viewing al the tip saw blade is formed.

  According to the bone resection tool of the present invention, it is possible to easily and highly accurately perform additional resection with a small size on the resection surface of the bone.

FIG. 1 is a perspective view of a bone resection instrument according to an embodiment of the present invention as seen from above. FIG. 2 is a perspective view of the bone resection tool according to the embodiment of the present invention as viewed from below. FIG. 3 is a perspective view of the blade body according to the embodiment of the present invention as seen from above. FIG. 4 is a perspective view of the blade main body according to the embodiment of the present invention as seen from below. FIG. 5 is a perspective view of the guide plate according to the embodiment of the present invention viewed from above. FIG. 6 is a perspective view of the guide plate according to the embodiment of the present invention seen from below. FIG. 7 is a perspective view of the bone resection instrument according to the embodiment of the present invention seen from above. FIG. 8 is a perspective view showing a usage state of the bone resection instrument according to the embodiment of the present invention. FIG. 9 is a side view showing a usage state of the bone resection tool according to the embodiment of the present invention. FIG. 10 is a perspective view showing a usage state of the bone resection instrument according to the embodiment of the present invention. FIG. 11 is a perspective view of the blade main body according to the modified example of the embodiment of the present invention as seen from above. FIG. 12 is a perspective view of a guide plate according to a modified example of the embodiment of the present invention as seen from above.

  Hereinafter, a bone cutting instrument according to an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, the bone resection device 1 is used in the artificial knee joint replacement technique when the resection surface of the bone of the part to be replaced is further excised by a predetermined thickness (1 mm in the present embodiment).

  The bone resection instrument 1 is an instrument that is used by being set on a bone saw hand piece 6 which is a high-speed electric vibration instrument (10,000 rotations / minute). The bone cutting instrument 1 includes a blade body 10 and a guide plate 20 that is located on the upper surface side of the blade body 10 and that guides a cutting position in the thickness direction by the blade body 10.

  The blade main body 10 has a substantially band-shaped flat plate shape, and a tip saw blade 12 formed on the tip edge in the longitudinal direction thereof, and a slide connection convex strip 13 formed on the upper surface thereof, which is a connection portion with the guide plate 20. , And a joint portion 18 that is a connecting portion with the handpiece 6 formed at the rear end portion (hand side portion).

  The tip edge of the blade body 10 has an arc shape that is convex toward the tip side, and the tip saw blade 12 is formed in an arc shape. When the blade main body 10 vibrates at a high speed in the width direction thereof, that is, in the extending direction of the tip saw blade 12, the bone of the portion in contact with the tip saw blade 12 is cut.

  The slide connecting ridge 13 extends upward from the rear end of the tip saw blade 12 of the blade body 10 toward the hand side in the center in the width direction. The width of the slide connecting ridge 13 is about half the width of the blade body 10. The thickness of the slide connecting ridge 13 is the same as the thickness of the tip saw blade 12 (1 mm), and the thickness of the blade body 10 at the slide connecting ridge 13 portion is twice that of the tip saw blade 12 (2 mm). Is.

  Notches are formed on both side edges of the slide connecting ridge 13 so as to incline in a direction in which the width narrows downward, and both side edges of the slide connecting ridge 13 are formed on the slide rail portion 29 of the guide plate 20 described later. The slide connection convex strip 13 is slidably held by the slide rail portion 29 by being inserted into the slide rail portion 29.

  The joint portion 18 is a portion fixed to the handpiece 6. The thickness of the joint portion 18 is 1.5 mm, which is thicker than that of the tip saw blade 12 and thinner than that of the slide coupling ridge 13.

  A thick plate portion 19 having the same thickness (2 mm) as that of the slide connecting ridge 13 is provided between the slide connecting ridge 13 and the joint portion 18. The thick plate portion 19 is installed over the entire width direction of the blade body 10.

  The elongated plate-shaped blade body 10 is driven by the handpiece 6 during cutting and vibrates at a high speed in the width direction. Therefore, when the blade body 10 is thin and has low bending rigidity, the blade body 10 bends at the time of high-speed vibration and the tip portion moves vertically. By doing so, the cutting system deteriorates. On the other hand, if the entire blade body 10 is thickened in order to increase the bending rigidity, the blade body 10 becomes heavy and stable high-speed vibration becomes difficult.

  On the other hand, as in the present embodiment, by installing the thick slide coupling ridge 13 and the thick plate portion 19 toward the center in the longitudinal direction of the blade body 10 to increase the bending rigidity of the blade body 10, It is possible to prevent the occurrence of bending and realize highly accurate cutting while suppressing the entire body from becoming heavy.

  Fastening holes 15 and 16 are formed at predetermined two positions in the longitudinal direction at the slide connecting convex portion 13 at the center in the width direction of the blade body 10. The slide positions of the guide plate 20 and the blade body 10 are fixed by using the fastening holes 15 and 16. The fastening holes 15 and 16 do not penetrate the blade main body 10 and are formed with a depth of 1 mm only in the portion of the slide connecting convex strip 13.

  The first fastening hole 15 is a hole for fixing the tip of the guide plate 20 to a protruding guide position where the tip of the guide plate 20 projects forward from the tip edge of the blade body 10 and guides, and the second fastening hole 16 of the guide plate 20. The tip is a hole for retreating from the tip edge of the blade body 10 and fixing it in a retracted position where no guidance is provided. 1 and 2 show a state in which the slide position of the bone resection instrument 1 is fixed to the protruding guide position, and FIG. 7 shows a state in which the protruding guide position is fixed to the retracted position.

  The guide plate 20 is in the form of a substantially flat plate having a width substantially the same as that of the blade body 10, and the length in the longitudinal direction is about three-fifths of that of the blade body 10. The guide plate 20 includes a distal end guide portion 21 installed at the distal end portion thereof, a rotary fastener 27 installed on the upper surface thereof, and a slide rail portion 29 extending longitudinally on the lower surface thereof. I have it.

  The leading end guide portion 21 is a rectangular flat plate portion that occupies an area of about a quarter on the leading end side of the guide plate 20, and has a rectangular opening window 22 located in the center. The two sides on the front end side and the rear end side that extend in the width direction of the opening window 22 are both arcuate shapes that are convex toward the front end side.

  By forming the opening window 22 at the tip of the guide plate 20, the tip saw blade 12 can be observed from above the blade body 10 through the opening window 22, and the bone cut by the tip saw blade 12 can be cut. The powder can be discharged through the opening window 22.

  The outer peripheral edges of the tip guide portion 21 are R surfaces 24 and 25, and the tip edge R surface 24 is formed on the tip portion and the outer edge R surfaces 25 are formed on both side portions. In this way, by making the outer periphery of the tip guide portion 21 into the R surfaces 24 and 25, the outer edge of the tip guide portion 21 that vibrates at high speed in the width direction at the time of cutting comes into contact with the bone, so that the bone is scraped or friction causes. It is possible to prevent the smooth high-speed vibration from being disturbed.

  An inner edge R surface 23 is formed on the inner side surface of the opening window 22. By forming the inner edge R surface 23 in this manner, high-speed vibration in the width direction of the tip guide 21 is smoothed, and when the cut chips of the bone are in a wet state, the inside of the opening window 22 It is possible to prevent the chips from diffusing to the surroundings by being sequentially solidified into a dumpling and then discharged.

  When the inner edge R surface 23 of the opening window 22 vibrates at least in the width direction, it is desirable that the inner edge R surface 23 be formed on two sides on both sides extending in the longitudinal direction orthogonal to the vibration direction. As in the case of the shape, it is desirable that it is formed on all four sides, including two sides extending in the width direction.

  The rotation stopper 27 is provided on the upper surface of the guide plate 20, and includes a rotation shaft 27b that is horizontal and parallel to the width direction, and a cylindrical protrusion 27a that is rotatable around the rotation shaft 27b. The cylindrical protrusion 27a is rotatable between a fastening position where it projects from the fastening hole 28 formed in the guide plate 20 to the lower surface side of the guide plate 20 and a retracted position which is retracted upward from the fastening position.

  By fitting the cylindrical projection 27a at the fastening position into the first fastening hole 15 or the second fastening hole 16, the blade body 10 and the guide plate 20 are fixed so as not to slide relative to each other, and the cylindrical projection at the retracted position. The blade body 10 and the guide plate 20 are slidable by removing 27a from the first fastening hole 15 or the second fastening hole 16.

  The slide rail portions 29 are installed on both edges of the lower surface of the guide plate 20 so as to extend in the longitudinal direction, and both side edges of the slide coupling convex strip 13 are slidably held by the slide rail portions 29. The slide rail portion 29 extends from the proximal end portion of the leading end guide portion 21 to the installation location of the rotary fastener 27 near the rear end of the guide plate 20.

  The guide plate 20 has a width of the tip guide portion 21 that is substantially the same as that of the blade body 10, but a narrower width from the tip guide portion 21 to the rear end side. A slightly wider size than 13.

  The configuration of the bone resection instrument 1 has been described above. Next, the usage mode of the bone resection instrument 1 will be described by taking as an example a case where the resection plane of the bone is additionally cut by 1 mm for adjustment. The bone resection instrument 1 is used by fixing the joint portion 18 to the connection portion of the handpiece 6, and by driving the handpiece 6, the blade body 10 vibrates in the width direction at high speed.

  FIG. 8 shows a state at the start of resection by the bone resection tool 1. FIG. 9A shows a state when the resection is started by the bone resecting instrument 1, and FIG. 9B shows a state in which about 70% of the resection surface is additionally excised. FIG. 10 shows a state in which the guide plate 20 is fixed in the retracted position and the remaining cut surface is being cut in a state where the guide is not performed.

  As shown in FIGS. 8 and 9 (a), at the time of starting the resection, the bone resecting instrument is placed so that the tip guide portion 21 of the guide plate 20 is located at the projecting guide position projecting to the tip side from the tip of the blade body 10. Fix the slide position of 1. The fixing of the sliding position is realized by inserting and fixing the cylindrical protrusion 27a of the rotary fastener 27 into the first fastening hole 15.

  At the start of cutting, the bone resecting instrument 1 fixed at the protruding guide position is such that the lower surface of the tip guide portion 21 contacts the resection surface of the bone 5 in parallel and the tip saw blade 12 of the blade body 10 causes the upper end portion of the bone 5. The cutting start position is set so as to contact the side surface of the.

  In this state, when the hand piece 6 is driven and the bone resection instrument 1 is vibrated at a high speed in the left and right directions in the width direction, the bone 5 at the portion where the tip saw blade 12 comes into contact is cut. Further, the operator pushes the handpiece 6 forward while pressing the guide plate 20 against the resection surface, the tip saw blade 12 is further pushed toward the tip side, and the upper end portion of the bone 5 is sequentially cut from the side. It

  In this way, the operator proceeds with the work while pressing the lower surface of the tip guide portion 21 of the guide plate 20 so that the lower surface of the tip guide portion 21 of the guide plate 20 always comes into contact with the resection surface of the bone 5, so that the tip saw blade 12 always operates at the initial resection surface. The position in the thickness direction is guided so as to be located in a region from 1 to 1 mm below, and the resection surface of the bone 5 is additionally excised sequentially from the end by a thickness corresponding to the thickness (1 mm) of the tip saw blade 12 ( See FIG. 9B).

  At this time, the cut chips of the excised bone 5 are sequentially gathered and solidified while colliding with the left and right inner edges at a high speed inside the opening window 22, and are sequentially discharged outside while forming a dumpling.

  In the region newly cut by the saw blade 12 in this manner, as shown in FIG. 9B, a new cut surface that is one step lower than the original cut surface is formed. The step between the original cut surface and the new cut surface corresponds to the thickness of the tip saw blade 12, which is about 1 mm in this embodiment.

  If the original cutting surface is cut and becomes smaller, the guide plate 20 cannot be pressed, and if the newly cut cutting surface becomes a certain size, the blade body does not need to be guided by the guide plate 20. By pressing the lower surface of the new cut surface 10 against the new cut surface and making parallel contact with the cut surface, the remaining original cut surface can be cut and removed (see FIG. 10).

  For example, as shown in FIG. 9 (b), after cutting about 70% of the cut surface in a side view, the remaining original cut surface is cut with a thickness of 1 mm without the guide plate 20 guiding. can do.

  Therefore, the remaining part of the original resection surface can be cut by the tip saw blade 12 of the blade body 10 without being guided by the guide plate 20 by the bone resection tool 1 whose slide position is fixed at the retracted position.

  As described above, according to the present embodiment, even when it is desired to additionally excise a smaller size with respect to the excised surface of the bone 5, the slide position of the guide plate 20 is fixed to the protruding guide position, and the distal end guide portion 21 is used. By cutting with the saw blade 12 of the tip of the blade body 10 while guiding, additional cutting can be performed accurately.

  Further, according to the present embodiment, by fixing the guide plate 20 in the retracted position, the blade body 20 is not guided by the guide plate 20 and is cut off by the tip saw blade 12 without being guided by the guide plate 20. You can also

  Further, according to the present embodiment, by forming the opening window 22, it is possible to perform the cutting while confirming the state of the tip saw blade 12, and the cutting chips of the cut bone 5 are exposed from the opening window 22 to the outside. It is also possible to prevent the chips from being discharged and the cutting chips being accumulated and becoming an obstacle to cutting.

  Next, a modified example of this embodiment will be described with reference to FIGS. 11 and 12. FIG. 11 shows a modification of the blade body 10. In the above-described embodiment, the blade body 10 vibrates at high speed in the width direction to cut the bone with which the tip saw blade 12 comes into contact. It is different in that it is provided with tip saw blades 12 'formed on the tip side surface and both side edge surfaces, and by vibrating the blade body 10' at high speed in the front-rear direction, the bone that the tip saw blades 12 'contact is cut. To do.

  The guide plate 20 can also be applied to the blade body 10 'having such a configuration, and the same effect as that of the above-described embodiment can be obtained.

  FIG. 12 shows a modification of the guide plate. The guide plate 20 'according to the present modification is different from the above-described embodiment in that the shape of the opening window 22' is a substantially square shape. Of course, the shape of the opening window may be circular or elliptical. The guide plate 20 'according to the present modification also has the same effects as the above embodiment.

  Although the embodiments of the present invention have been described above including the modified examples, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. . For example, the shape, size, material and the like of the members forming the bone resection tool can be changed as appropriate.

  Further, the bone resection instrument according to the present embodiment is not limited to artificial joint replacement surgery, and can be widely applied to the case of additionally resecting the whole or a part of the resection surface of bone.

DESCRIPTION OF SYMBOLS 1 Bone excision instrument 10 Blade main body 12 Tip saw blade 13 Slide connection convex strip 15 First fastening hole 16 Second fastening hole 18 Joint portion 19 Thick plate portion 20 Guide plate 21 Tip guide portion 22 Opening window 23 Inner edge R surface 24 Tip Edge R surface 25 Outer edge R surface 27 Rotating fastener 27a Cylindrical projection 27b Rotating shaft 28 Fastening hole 29 Slide rail portion 5 Bone 6 Handpiece

Claims (6)

In a bone cutting instrument for cutting bone,
Having a tip saw blade, by vibrating at high speed, a substantially flat blade body for cutting the bone with which the tip saw blade contacts,
A guide plate that has a substantially flat plate-shaped tip guide portion, is located on the upper surface side of the blade body, and is slidably connected to the blade body relatively in the front-rear direction. A protruding guide position that projects to the tip side of the tip saw blade of the blade main body and covers the tip saw blade, guides the cutting position in the thickness direction by the tip saw blade, and the tip guide portion recedes from the tip saw blade. Guide plate that can slide between the retracted position and
A bone resecting instrument comprising:   The opening window for visually recognizing the tip saw blade from above when the tip guide portion is located at the protruding guide position is formed in the tip guide portion. Bone cutting instrument.   The bone resection instrument according to claim 2, wherein a side surface inside the opening window of the distal end guide portion is an R surface.   The bone resection instrument according to any one of claims 1 to 3, wherein an outer side surface of the tip guide portion is an R surface. The bone resecting instrument according to claim 1 , wherein the guide plate further includes a fastener for fixing the sliding position of the guide plate to the protruding guide position or the retracted position. Tip saw blade has, by high-speed vibration in the tip guide plate saw blade is used is attached to the substantially flat blade body for cutting Rukotsu be contacted,
A substantially flat plate-shaped tip guide part,
A slide rail portion that holds the blade body from the upper surface side,
Equipped with
The tip guide portion projects toward the tip side from the tip saw blade of the blade body and covers the tip saw blade, and a protruding guide position for guiding the cutting position in the thickness direction by the tip saw blade, and the tip guide portion. Between the retracted position retracted from the saw blade, while being slidably connected to the blade body in the front-rear direction,
The guide plate, wherein an opening window is formed in the tip guide portion for visually recognizing the tip saw blade from above when the tip guide portion is located at the protruding guide position.

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