JPH0246835A - Surgical extirpation apparatus - Google Patents

Abstract

PURPOSE:To obtain a low-cost high-safety excellent cutting performance surgical extirpation apparatus, by constructing it in such a manner that its shear angle defined by its outer edge and its shear edge portion is varied in accordance with each shearing process. CONSTITUTION:Its inner edge 18 located inwardly of its outer edge 14 includes two acute boring cutting edges 26, 26 opposed to each other in the direction of its diameter each of which edge is V-sheapedly on each tip portion thereof, and acute shearing cutting edges 27, 27 each of which is circularly formed on each of its side walls, and, in the case of extirpating the semicircular plate of a knee joint, the semicircular plate is taken in between notch portions 23, 23 which are made in a pair, so that shearing of the plate is carried out at each of its side faces by each of cutting edges 24 and each of the shearing cutting edges 27 as boring cutting thereof is carried out by each the boring cutting edges 26, 26 to extirpate the living organism; at the beginning of the shearing each of the cutting edges 24 and the tip portion 27b of each of the shearing cutting edges 27 cut it. Each of the cutting edges 24 and the rear portion 27b of each of the shearing cutting edges 27 then cut it in the course of the cutting process and its shear angle theta defined by each of the cutting edges 24 and each of the shearing cutting edges 27 becomes smaller with the progress of the shearing process. Sudden increases of shearing forces can therefore be prevented, so that the apparatus can be improved into one which is low-costed and of high safety and good cutting performance.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention can be used to treat cartilage (articular meniscus, articular cartilage) in joint cavities such as knees, arthrosis,
The present invention relates to a surgical resection instrument for resecting a tumor or the like and ejecting it out of a body cavity.

[Prior Art and Problems to be Solved by the Invention] Conventionally, joint surgery has mainly been performed using an incisional method (open surgery). For example, in general joint surgery, 111
These surgeries required relatively large incisions, such as removing a tumor on the lid 1-1 and removing damaged cartilage, bone, etc. from the knee +11fij. This has the drawback of causing trauma due to the incision, causing pain and restricting movement, and requiring a long time for complete recovery.

In recent years, surgical resection instruments have been developed in which a small puncture hole is formed in the joint without making an incision based on the observation of the joint Mt (endoscope), and the insertion part is inserted into this puncture hole. is proposed. For example, JP-A-61-170449 discloses a surgical cutting instrument that has an insertion section inserted through a hard, linearly extending inner tube that has a cutting section at its tip inside a hard, linearly extending outer tube. Disclosed. This surgical resection instrument bores tissue at the tip of the inner tube and shears the tissue at the side opening near the tip.The blade for cutting this tissue is cylindrical. an outer cutter provided in the axial direction on the outer tube; and an inner cutter rotatably inserted into the outer cutter, with a fishtail-shaped cutting blade at the tip and a spiral cutting blade on the side. (helical cutter blade).

Further, German Utility Model No. 8707238 discloses a surgical cutting instrument in which an inner blade with a spiral blade at the tip is formed hollow, and this hollow part is connected to a suction device. ing.

By the way, in the above conventional technology, when the inner cutter cooperates with the opening of the outer cutter to shear the tissue, the A7-angle (shear angle) θ is formed in a helical shape by the cutting edge on the side surface of the inner cutter. Therefore, it remained constant as shown in Figure 23.

Here, the shearing force P (Kg) is expressed by the following formula.

P-t2 r/ (2tan O) t: Thickness of sheared tissue (maro) τ: Shear resistance (KgZ order 2) From the above equation, when t and τ are constant, the shear force P is the shear angle θ
If I is constant, smooth shearing as shown by the broken line in FIG. 24 should occur without fluctuation. However, in reality, as shown by the solid line in the figure, D increases sharply at the beginning of the shearing process, and then C decreases and becomes constant. If the shearing force suddenly increases in this way, the rotational speed will change, resulting in a loss of sharpness, and repeated stress will be applied to the cutting edge, making it susceptible to fatigue failure and unsafe.

Furthermore, forming the inner blade side surface into a spiral cutting edge is an advantageous process.
The problem is that it is difficult and expensive.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a surgical cutting instrument that is highly safe, inexpensive, and sharp.

[Means and Effects for Solving the Problems 1] The external H cutting instrument of the present invention is equipped with an outer cutter having a blade portion and an inner cutter disposed on the right side of the shearing blade portion. The shearing angle formed by the shearing process is changed by the shearing process.

In the present invention, the shearing begins! The shearing angle during shearing is smaller than the 79Ifi angle.

Examples] Hereinafter, the present invention will be described in detail with reference to the drawings.

1 and 11 relate to a first embodiment of the present invention, FIG. 1 is a sectional view of the distal end of a surgical cutting instrument, and FIG.
3 is a sectional view taken along line A-A in the figure, FIG. 3 is a sectional view taken along line B-8 in FIG.
FIG. 5 is a perspective view of the inner cutter, FIG. 6 is a perspective view showing the outer cutter and the inner cutter inserted into the outer cutter, and FIG. 7 is a front view of the inner cutter.
Figure 8 is a view taken along the line C-C in Figure 7, Figure 9 is a view taken along the line D-D' in Figure 7, Figure 10 is an enlarged view of the inner blade, and Figure 11 is a surgical FIG. 2 is an explanatory diagram that does not show the configuration of the cutting instrument.

In FIG. 11, a surgical resection instrument 1 includes a rigid, straight-shaped insertion section 2, and a main body section 3 connected to the rear of the insertion section 2. As shown in FIG. A power cord 6 is connected to the rear end of the main body 11i113, and this power cord 6 allows power to be supplied from the control unit 4 to a driving CJ device, such as a motor, provided in the main body 3. It has become.

A foot switch 9 is connected to the control unit 4, so that the operator operating the surgical resection instrument 1 can control the Tanabata drive using his or her feet. Furthermore, a suction device 7 is connected to the rear end of the main body 3 by a tube 8 for discharging the excised fragments of the living body II from the body.

As shown in FIG. 4, the insertion section 2 includes a rigid, linear outer tube 11 and an inner tube 12 inserted into the outer tube 11. This outer tube 11 is a tube member 13 that is open at both ends.
A substantially cylindrical outer blade 14 made of stainless steel is provided at the other end of the tube member 13, and the other end is detachably connected to the front part of the main body 3. A cylindrical connecting member 16 is fixed with solder or the like.

Further, the inner tube 12 has a tube member 17 having an outer diameter slightly smaller than the inner diameter of the outer tube 11. This tube member 17 is open at both ends, and an inner cutter 18 made of stainless steel is fitted onto the end on the outer cutter 14 side.

The outer diameter of the inner cutter 18 is slightly smaller than the inner diameter of the outer cutter 14, so that the inner cutter 18 can be rotated through the outer cutter 14. Furthermore, a substantially cylindrical sleeve is fitted onto the other end of the tube member 17 . A suction path 21 provided in the tube member 17 is provided on the peripheral wall of the sleeve 19.
Further, this sleeve 19 is connected to a motor provided in the main body 3 so that rotational force can be transmitted to the inner tube 12.

In FIGS. 1 and 3, the outer cutter 14 opens forward, and the peripheral wall has a pair of notches 23.2 cut from the front end.
3 is provided, and cutting edges 24, 24 are formed at the edges located in the longitudinal direction of this notch 23. The inner cutter 18 is located within the outer cutter 14. This inner blade 1
The tip of 8 has two diametrically opposed sharp edges for boring cutting.
The peripheral wall of the inner cutter 18 has a shearing cutting edge 27.27 as a sharp shearing edge portion formed in an arc shape, and a window 28 communicating with the suction path 21 of the tube member 17 is provided at the front end. There is. As shown in FIGS. 7 and 9, this shearing cutting edge 27 is formed by cutting diagonally from the front with a cylindrical cutting tool 29.

The operation of the surgical cutting instrument 1 configured as described above will be explained.

For example, when removing the meniscus of a knee joint, the meniscus is inserted between a pair of notches 23 and 23, and the boring cutting blade 26
While performing boring cutting, the cutting blade 24 and the shearing blade 27 perform shearing on the side surface to remove living tissue. 5 and 6, to explain the 9g cutting stroke, cutting is performed by the cutting blade 24 and the tip portion 27a of the shearing cutting blade 27 at the beginning of shearing. As cutting progresses, cutting is performed by the contact portion 27b of the cutting blade 24 and the shearing cutting blade 27. Furthermore,
To explain using FIG. 10, as the rfJ cutting stroke progresses, since the shearing cutting blade 27 is formed in an arc shape, the angle formed between the cutting blade 24 and the shearing cutting blade 27 becomes 1, that is, A7 - angle θ. gradually becomes smaller, and if the shear angle A7- formed by the cutting blade 24 at the beginning of shearing and the tip 27a of the shearing cutting blade 27 is 01, and the shear angle θ2 during shearing is taken, the relationship θ1>θ2 holds.

Here, if the shear angle θ is constant, the shear force P at the beginning of shearing
increases as shown in Fig. 24, but since the shear angle is changed as described above and the shear angle is increased at the beginning of shearing, the shear force P is calculated by the formula of /(2tanθ) at p, , = t2. doesn't get bigger. Therefore, at the beginning of shearing, shear force P
This prevents the sharp increase in sharpness, the rotational speed does not change significantly, and the sharpness is improved compared to the conventional method. Moreover, since the repetitive load applied to the cutting edge is reduced, fatigue failure of the cutting edge is less likely.

12 to 16 relate to the second embodiment of the present invention,
Fig. 12 is a perspective view of the inner cutter, Fig. 13 is a perspective view showing the state of the outer cutter and the inner cutter inserted into the outer cutter, Fig. 14 is a front view of the inner cutter, and Fig. 15 FIG. 14 is a view taken along the line EE in one direction, and FIG. 16 is a view taken along the FF direction shown in FIG. 14.

The inner cutter 31 of this embodiment has a V-shaped boring cutting edge 26 formed at its tip, similar to the first embodiment.

The same circular arc part 33 is formed in the axial plane part 32 forming this boring cutting blade 26 from the boring cutting blade 26 to the peripheral wall of the inner cutter 31, and the shearing blade is formed by this circular arc part 33 and the peripheral wall. A shearing cutting edge 34 is formed as a section.

Further, a window 28 communicating with the suction path 21 of the tube member 17 is provided at the front end of the inner cutter 31 .

Furthermore, in FIGS. 14 to 16, the shearing cutting blade 34 is located diagonally in front of the cylindrical cutting tool 36, and the inner cutter 31
It is formed by cutting to intersect the longitudinal center of the.

In this embodiment as well, the shearing blade 34 is formed in an arc shape as in the first embodiment, so that the cutting blade 34 formed on the outer blade 14
4, the shear angle θ changes according to the gqrJII process, and the shearing force P at the beginning of shearing does not increase suddenly.

Other configurations and operations are the same as those in the first embodiment.

17 to 22 relate to the third embodiment of the present invention,
Fig. 17 is a perspective view of the inner cutter, Fig. 18 is a perspective view showing the state of the outer cutter and the inner cutter inserted into the outer cutter, Fig. 19 is a front view of the inner cutter, and Fig. 20 is the 19th G-G' direction arrow view in the figure, 2nd
1 is a view taken along the H-11 direction in FIG. 19, and FIG. 22 is a view taken along the I-I direction in FIG. 19.

The distal end surface of the inner cutter 41 in this embodiment is notched in a V-shape to form a boring cutting edge 42. Furthermore, a part of the tip peripheral wall 45 is cut off to form an opposing flat part 46,
A cutting edge 43 is formed at one edge of the flat portion 46, 46 and the peripheral wall 45, which extends in the direction of the cutting hand. Further, a window 44 communicating with the suction path 21 is provided in the plane portion 46 .

On the side opposite to the cutting edge 43, the flat portion 46 has an arcuate portion 4.
7 is formed, and an arc-shaped shearing cutting blade 48 as a shearing blade part is formed at the edge of this circular arc part 47 and the peripheral wall 45.

Furthermore, in FIGS. 19 to 22, the shearing cutting blade 48 is formed into a cylindrical shape by being cut obliquely from the front with a cutting tool 49.

In the case of this embodiment, as in the first embodiment, the shearing cutting blade 48 is formed in an arc shape, so that the shear angle θ between the shearing cutting blade 48 and the cutting blade 24 is large at the beginning of shearing. Therefore, the shearing blade P at the beginning of shearing does not increase rapidly.

Other configurations and operations are similar to those of the first embodiment.

Note that the shapes of the inner cutter and outer cutter are not limited to the above embodiments,
Any shape may be used as long as it has an arc-shaped shearing cutting edge and the shear angle between this shearing cutting edge and the cutting edge provided on the outer blade decreases from the beginning of shearing as the shearing progresses. .

Further, the material of the inner cutter and the outer cutter does not need to be stainless steel, and any material may be used as long as it can be used as the iU of a cutter, such as ceramics or tool steel.

[Effects of the Invention] As explained in F-F below, according to the present invention, the shearing angle between the shearing blade part and the blade part of the outer cutter is formed so as to change depending on the shearing process, thereby preventing a sudden increase in shearing force. It is highly safe, inexpensive, and has good sharpness.

[Brief explanation of the drawing]

1 and 11 relate to a first embodiment of the present invention, FIG. 1 is a sectional view of the distal end of a surgical cutting instrument, and FIG.
3 is a sectional view taken along line BB in FIG. 1, and FIG. 4 is a sectional view of the inner tube inserted into the outer tube.
Fig. 5 is a perspective view of the inner cutter, Fig. 6 is a perspective view of the outer cutter and the inner cutter inserted into the outer cutter without showing the state thereof, and Fig. 7 is a front view of the inner cutter.
Figure 8 is a C-C = direction arrow view of Figure 7, Figure 9 is a DD one-way arrow view of Figure 7, Figure 10 is an enlarged view of the inner cutter, and Figure 11 is an enlarged view of the inner cutter.
The figure is an explanatory view showing the configuration of a surgical cutting instrument, and Figures 12 to 16 relate to a second embodiment of the present invention, with Figure 12 being a perspective view of the inner cutter, and Figure 13 showing the outer cutter and the outer cutter. Fig. 14 is a front view of the inner cutter, Fig. 15 is a perspective view showing the state of the inner cutter inserted into the
The figure is a view taken along the E-E' direction in Fig. 14, and Fig. 16 is a view of the 14th
17 to 22 relate to the third actual droplet example of the present invention, FIG. 17 is a perspective view of the inner cutter, and FIG. 18 is an outer cutter and the inside of the outer cutter. Fig. 19 is a front view of the inner cutter, Fig. 20 is a view taken along the direction arrow G-G in Fig. 19, Fig. 21 is a view showing the state of the inner cutter inserted in Fig. H-1-4
= Direction arrow view, Figure 22 is a 1-1'' direction arrow view in Figure 19, Figures 23 and 24 relate to the conventional example, Figure 23 is an explanatory diagram of the shear angle, and Figure 24 is a diagram showing the shear angle. It is an explanatory view of shearing force that changes depending on the shearing stroke. 1... Surgical cutting instrument 2... Insertion part 11... Outer tube 12... Inner tube 14... Outer blade
18... Inner blade 23... Notch - 24... Cutting blade 26... Boring VJ blade 27... Shearing cutting blade Figure 2 Figure 6 Figure 4 Figure 10 Figure 5 Figure 7 Figure 6 Figure 8 Figure 17 Figure 19/ Figure 21 PJ,,6+-,]1? Power to sin P′ [kql Figure 18 Figure 20 Figure 22

Claims (1)

[Scope of Claims] An inner cutter is rotatably provided within a cylindrical outer cutter having a tip opening forward and a cutting portion in the axial direction of the tip, and a shearing cutter provided on the side surface of the inner cutter. A surgical resection instrument for shearing living tissue between a blade portion and a blade portion of the outer cutter, characterized in that a shearing angle between the shearing blade portion and the blade portion of the outer cutter changes depending on the shearing process. surgical cutting instruments.