JPH0481459B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention provides a method for transferring blood from outside the body cavity to inside the body cavity without making an incision.
For example, the present invention relates to a surgical resection instrument for removing cartilage (articular meniscus, articular cartilage), articular aneurysm, tumor, etc. in a joint cavity of a knee or the like, and draining the cartilage out of the body cavity.

[Prior Art and Problems to be Solved by the Invention] Conventionally, joint surgery has been mainly performed by an incision method (open surgery). For example, common joint surgeries include removing tumors on the patella and removing damaged cartilage, bone, etc. from the knee joint, but these surgeries require relatively large incisions. This has the drawback of causing trauma due to the incision, causing pain and restricting movement, and requiring a long time for complete recovery.

Therefore, in recent years, surgical resection instruments have been proposed that perform surgery by forming a small puncture hole in the joint without making an incision under arthroscopic (endoscope) observation, and inserting the insertion part into this puncture hole. has been done. For example, Tokukai Akira
Japanese Patent No. 61-170449 discloses a surgical intermediate instrument having an insertion portion inserted through a hard, linearly extending inner tube having a cutting portion at the distal end of the hard, linearly extending outer tube. This surgical resection instrument is designed to bore tissue at the tip of the inner tube and shear the tissue at the side opening near the tip, and the blade for cutting this tissue is a cylindrical blade. An outer cutter is provided in the axial direction on the outer tube, and an inner cutter is rotatably inserted into the outer cutter and has a fishtail-shaped cutting edge at the tip and a spiral cutting edge on the side. It consisted of a helical cutter blade).

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

By the way, in the above conventional technology, the shear angle (shear angle) θ when the inner cutter cooperates with the opening of the outer cutter to shear the tissue is such that the cutting edge on the side surface of the inner cutter has a helical shape.
Because it was formed as shown in FIG. 23, it remained constant.

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

P=t ² τ/(2tan θ) t: Thickness of the tissue to be sheared (mm) τ: Shear resistance (Kg/mm ² ) From the above equation, if t and τ are constant, the shear force P is the same as the shear angle θ If so, smooth shearing as shown by the broken line in FIG. 24 should occur without any fluctuation. However, in reality, as shown by the solid line in the same figure, it rapidly increases at the beginning of the shearing process, then decreases and becomes constant. If the shearing force increases rapidly in this way, the rotational speed will change, resulting in a loss of sharpness, and repeated stress will be applied to the cutting edge, which is likely to cause fatigue failure and is not safe. Furthermore, forming the inner cutter side surface into a spiral cutting edge has the problem that machining is difficult and expensive.

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

[Means and effects for solving the problem] The surgical cutting instrument of the present invention includes an outer blade having a blade portion and an inner blade having a shearing blade portion,
The shearing angle between the outer blade and the shearing blade section is formed to change depending on the shearing process.

In the present invention, the shear angle during shearing is smaller than the shear angle at the beginning of shearing.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

1 and 11 relate to a first embodiment of the present invention, in which FIG. 1 is a cross-sectional view of the tip of the surgical cutting instrument, FIG. 2 is a cross-sectional view along the line A-A' in FIG. 3
The figure is a sectional view taken along the line B-B' in Figure 1, Figure 4 is a sectional view of the inner tube inserted into the outer tube, Figure 5 is a perspective view of the inner cutter, and Figure 6 is the outer cutter and the inside of the outer cutter. Fig. 7 is a front view of the inner cutter, Fig. 8 is a perspective view showing the state of the inner cutter inserted into the
The figure is a C-C' direction arrow view of FIG. 7, FIG. 9 is a D-D' direction arrow view of FIG. 7, and FIG. 10 is an enlarged view of the inner cutter.
FIG. 11 is an explanatory diagram showing the configuration of the surgical 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 3, and this power cord 6 allows power to be supplied from the control unit 4 to a drive device, such as a motor, provided inside the main body 3. It's getting old. A foot switch 9 is connected to the control unit 4, so that the operator operating the surgical cutting instrument 1 can control the drive of the motor with his/her foot. Furthermore, a suction device 7 is connected to the rear end surface of the main body 3 by a tube 8 for discharging the excised living tissue fragments from the body.

As shown in FIG. 4, the insertion section 2 includes a rigid outer tube 11 formed in a straight line, and an inner tube 12 inserted into the outer tube 11. This outer tube 11 has a tube member 13 that is open at both ends.
A substantially cylindrical outer cutter 14 made of stainless steel is provided at the other end of the main body 3.
A cylindrical connecting member 16 that is removably connected to the front part of the housing 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 rotate relative to the outer cutter 14. Further, a substantially cylindrical sleeve 19 is fitted onto the other end of the tube member 17 . A tube member 17 is provided on the peripheral wall of this sleeve 19.
A communication hole 22 that communicates with a suction path 21 provided therein.
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 is provided with a pair of notches 23, 23 cut from the front end.
Cutting blades 24, 24 are provided at the edges located in the longitudinal direction of 3.
is formed. The inner cutter 18 is located within the outer cutter 14. The tip of this inner cutter 18 has two diametrically opposed sharp boring cutting edges 26, 26 formed in a V-shape for performing boring cutting, and the peripheral wall of this inner cutter 18 is formed in an arc shape. It has shearing blades 27, 27 as sharp shearing blade parts, and a window 28 communicating with the suction path 21 of the tube member 17 on the front end surface.
is provided. 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 the pair of notches 23 and 23, and while boring is performed using the boring cutting blade 26, the cutting blade 24 and the shearing cutting blade 27 are removed from the side. Shearing is performed to remove the living tissue. In Figures 5 and 6,
To explain the shearing process, at the beginning of shearing, cutting is performed by the cutting blade 24 and the tip portion 27a of the shearing cutting blade 27. As the cutting progresses, the cutting blade 24 and the shearing cutting blade 2
Cutting is performed by the rear part 27b of 7. Furthermore, as explained using FIG. 10, as the shearing 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,
That is, the shear angle θ gradually decreases, and if the shear angle between the cutting blade 24 at the beginning of shearing and the tip 27a of the shearing cutting blade 27 is θ1, and the shear angle θ2 during shearing is the shear angle θ2, the relationship θ1>θ2 is established.

Here, if the shear angle θ is constant, the shear force P will be large at the beginning of shearing as shown in Figure 24, but since the shear angle is changed as described above and the shear angle is increased at the beginning of shearing, P The shearing force P does not increase due to the formula =t ₂ τ/(2tanθ). Therefore, it is possible to prevent the shearing force P from increasing rapidly at the beginning of shearing, the rotational speed does not change significantly, and the sharpness is improved compared to the conventional one. Moreover, since the repetitive load applied to the cutting edge is reduced, fatigue failure of the cutting edge is less likely to occur.

12 to 16 relate to the second embodiment of the present invention, FIG. 12 is a perspective view of the inner cutter, and FIG. 13 is a perspective view showing the state of the outer cutter and the inner cutter inserted into the outer cutter. Figure 14 is a front view of the inner cutter, Figure 15 is the 14th
The E-E′ direction arrow view in the figure, Fig. 16 is F in Fig. 14.
-F′ direction arrow view.

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 axial plane portion 3 forming this boring cutting edge 26
2, the same circular arc part 33 is formed from the boring cutting blade 26 to the peripheral wall of the inner cutter 31, and this circular arc part 33 and the peripheral wall form a shearing cutting blade 34 as a shearing blade part. . Further, at the front end of the inner cutter 31, a window 28 communicating with the suction path 21 of the tube member 17 is provided.
is provided.

Furthermore, in FIGS. 14 to 16, the shearing cutting edge 34 is formed by cutting with a cylindrical cutting tool 36 diagonally forward and intersecting the longitudinal center of the inner cutter 31. There is.

In this embodiment, the shearing blade 34 is similar to the first embodiment.
is formed in an arc shape, and therefore the angle formed with the cutting edge 24 formed on the outer cutter 14, that is, the shear angle θ, changes depending on the shearing process, and the shearing force P at the beginning of shearing increases rapidly. There is no such thing.

The 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, and FIG. 18 is a perspective view showing the state of the outer cutter and the inner cutter inserted into the outer cutter. Figure 19 is a front view of the inner cutter, Figure 20 is the 19th
FIG. 21 is a view taken along the line G-G' in the figure, FIG. 21 is a view taken along the line H-H' in FIG. 19, and FIG.
It is an arrow view in the I′ direction.

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, and a cutting edge 43 is formed at one edge extending in the longitudinal direction between the flat parts 46, 46 and the peripheral wall 45. has been done. Further, a window 44 communicating with the suction path 21 is provided in the plane portion 46 .
On the opposite side of the cutting blade 43, a circular arc portion 47 is formed in the plane portion 46, and an arc-shaped shearing cutting blade 48 as a shearing blade portion is formed at the edge of the circular arc portion 47 and the peripheral wall 45. is formed.

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 well, the shearing cutting blade 48 is formed in an arc shape as in the first embodiment.
The shear angle θ between the cutting edge 8 and the cutting edge 24 is large at the beginning of shearing. Therefore, the shear force 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 the outer cutter are not limited to the above-mentioned embodiments, and each has an arc-shaped shearing cutting edge, and the shear angle formed by this shearing cutting edge and the cutting edge provided on the outer blade is the point at which the shearing begins. Any shape may be used as long as it decreases as the shear progresses.

Furthermore, the material of the inner cutter and the outer cutter does not need to be stainless steel, and may be any material that can be used as a material for cutlery, such as ceramics or tool steel.

[Effects of the Invention] As explained above, according to the present invention, the shearing angle between the shearing blade part and the blade part of the outer cutter is formed to change according to 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, in which FIG. 1 is a cross-sectional view of the tip of the surgical cutting instrument, FIG. 2 is a cross-sectional view along the line A-A' in FIG. 3
The figure is a sectional view taken along the line B-B' in Figure 1, Figure 4 is a sectional view of the inner tube inserted into the outer tube, Figure 5 is a perspective view of the inner cutter, and Figure 6 is the outer cutter and the inside of the outer cutter. Fig. 7 is a front view of the inner cutter, Fig. 8 is a perspective view showing the state of the inner cutter inserted into the
The figure is a C-C' direction arrow view of FIG. 7, FIG. 9 is a D-D' direction arrow view of FIG. 7, and FIG. 10 is an enlarged view of the inner cutter.
FIG. 11 is an explanatory diagram showing the configuration of a surgical cutting instrument;
12 to 16 relate to the second embodiment of the present invention, FIG. 12 is a perspective view of the inner cutter, and FIG. 13 is a perspective view showing the state of the outer cutter and the inner cutter inserted into the outer cutter. figure,
Fig. 14 is a front view of the inner cutter, Fig. 15 is a view taken along the E-E' direction in Fig. 14, and Fig. 16 is a view taken from F-- in Fig. 14.
F′ direction arrow view, FIGS. 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 a front view of the inner cutter.
The figure is a view taken along the line G-G' in FIG. 19, FIG. 21 is a view taken along the line H-H' in FIG. 19, and FIG.
The I-I′ direction arrow view in FIG. 9, FIGS. 23 and 24 relate to the conventional example, FIG. 23 is an explanatory diagram of the shear angle, and FIG. 24 is an explanatory diagram of the shear force that changes depending on the shear stroke. It is a diagram. DESCRIPTION OF SYMBOLS 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 cutting blade, 27
...shear cutting blade.

Claims (1)

[Scope of Claims] 1. An inner cutter is rotatably provided within a cylindrical outer cutter which has a front end portion of the tube member that opens forward and has a cutting portion in the axial direction of the end portion, and an inner cutter is provided rotatably on the side surface of the inner cutter. A surgical resection instrument that shears living tissue between a provided shearing blade portion and a blade portion of the outer cutter, and has a suction path communicating with the opening of the distal end portion and suctions the excised tissue, The shearing blades are a pair, and each shearing blade has a shape such that the shearing angle formed by the outer blade becomes smaller during the shearing process, and each shearing blade has a suction path for the pipe member. A surgical resection instrument characterized by being provided with a suction window that communicates with the outside.