JPH053880A - Saw for operation and guide member for collimation - Google Patents

Abstract

PURPOSE:To prevent the wear, deformation and displacement of the saw blade and to allow the exact conduction of a bone removing operation by providing a tooth part formed alternately with plural pieces of specific teeth at the front end of the saw blade and forming a step part on a guide surface of the guide piece of a guide member on the side in contact with the bone. CONSTITUTION:The saw blade 20 for operation is arranged alternately with horizontal teeth 22a directed to the longitudinal direction of a body part 21 and deflecting teeth 22b having a prescribed expanding angle in an upward direction at one end of the body part 21 at its center, by which the single deflecting tooth-shaped tooth part 22 is formed. The generation of an error in the cutting of the bone is obviated as far as the saw blade is used in such a manner as to prevent the deflecting tooth 22b from heading toward the cutting surface of the bone even if the deflecting tooth 22b is deformed and damaged according to such saw blade. On the other hand, the guide member 10 for collimation guiding the slaw blade 20 forms a step part 13 on the guide surface 12a of the guide piece 12 positioned on an upper side on the side in contact with the bone in the tooth member slit 11b of a guide slit 11. The clattering and angle deflection of the saw blade 20 is prevented in this way.

Description

Detailed Description of the Invention

[0001]

[Industrial application] The present invention is used in the field of medical orthopedics to repair osteoarthritis or artificial joint replacement in order to restore the joints of the human body that have been deformed by diseases such as rheumatoid arthritis and osteoarthritis. The present invention relates to a surgical saw blade and an aiming guide member used for excising a repaired portion during a surgical operation.

[0002]

BACKGROUND OF THE INVENTION Presently, orthopedic surgeons use various shapes of saws during surgery. A swing saw is known as one of such saws, and is designed to cooperate with an aiming guide member that guides the swing of the saw to cut bone tissue during surgery. There is.

A conventional saw blade 20 is shown in FIG. 5, and the saw blade 20 made of stainless steel has a body portion having an elongated shape in the center.
21 is a double-sided rung-like tooth portion 22 composed of run-out teeth 22b having a runout width t ₂ at one end and having runouts in the vertical direction.
, And at the other end, a swing sawing device (not shown)
Multiple mounting holes for attaching to the chucking part of
A handle 23 having a 23a is arranged.

When performing bone resection, saw cutting 20
The oscillating saw cutting device that oscillates the saw has a motor that is operated electrically, hydraulically, or pneumatically, and this motor oscillates the saw cutting 20 in a controllable manner.

Next, FIG. 6 shows a guide member 10 made of stainless steel which operates in cooperation with the saw blade 20 as described above, and the saw blade 20 is inserted into the guide member 10 to guide the saw blade 20. Two guide slits 11 sandwiched by two guide pieces 12 arranged in parallel at the symmetrical positions are provided.
The surface of the guide piece 12 facing the guide slit 11 is a parallel guide surface 12a, and the gap s ₁ of the guide slit 11 is slightly larger than the swing width t ₂ of the saw blade 20. I am doing it. This is because in the bone resection using the saw cutting 20 in combination with the guide member, it is often necessary to bring the guide member 10 into contact with the vicinity of the cut portion of the bone. In such a case, the saw cutting 20 is used as the guide member. This is because it must be inserted into the guide slit 11 from the rear of 10.

[0006]

2. Description of the Related Art By performing bone resection using the saw 20 and the guide member 10 in combination, it is possible to perform regular bone resection with the saw 20 being guided by the guide member 10.

However, the following problems exist in the bone resection method using the conventional sawing 20 and the guide member 10 in combination.

First, since the tooth portion 22 of the conventional sawing 20 has a double run-out tooth shape including run-out teeth 22b each having a predetermined spread angle in both up and down directions, for example, from direct contact with the guide surface 12a. 22b due to direct contact with other instruments used for surgery or due to pressure, impact, etc.
Wear and row deformation easily occur. If wear, deformation, etc. occur, even if the saw cutting 20 is guided at an accurate angle,
An error will occur accordingly.

Further, the gap s ₁ between the slits of the guide member 10
Is slightly larger than the tooth run-out width t ₂ of the run-out teeth 22b of the saw cutting 20 as described above, and therefore considerably thicker than the thickness t ₁ of the main body portion 21, rattling of the saw cutting 20 and angular runout occur,
Therefore, there is a problem that an error occurs in the bone resection work.

In artificial joint replacement, loosening of the installed artificial joint has various adverse effects on the living body, and therefore very accurate bone resection work is required. In particular, in the case of surgery to replace a part of the living bone with an artificial joint having a porous surface, it is very necessary to cut the bone smoothly and accurately because the surrounding living bone grows in the hole. is important. Since the resection surface of the bone strengthens the fitting and setting force of the artificial joint, a uniform weighted supporting force for the bone is promoted, and the alignment of the artificial joint and the excised bone is improved. However, the combination of the conventional sawing 20 and the guide member 10 described above does not always allow the bone to be cut into a smooth and accurate shape.

[0011]

SUMMARY OF THE INVENTION To solve the above problems, the present invention provides a surgical saw blade for use with an aiming guide member having two parallel guide pieces, in which the tooth portion has a eccentric tooth shape. Further, in the aiming guide member having the two parallel guide pieces, a step portion is formed on at least one guide surface of the guide piece on the side in contact with the bone.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings. FIG. 1 shows that the guide member 10 of the present invention is installed in the tibia 50 by the installation jig 30 of the guide member 10 and the Kirschner wire 40, and the proximal end of the tibia 50 is excised using the saw 20 of the present invention. I will show you how. While oscillating the saw cutting 20 by operating the swing saw cutting device 60, the saw slit 20 is guided by the guide slit 11 of the guide member 10 and pushed forward to cut off the proximal end of the tibia 50. Enforced.

The surgical saw blade 20 made of stainless steel according to this embodiment is shown in FIG.
2, the saw cutting 20 has an elongated main body portion 21 at the center thereof, horizontal teeth 22a oriented in the longitudinal direction of the saw cutting main body portion 21 at one end, and a predetermined upward direction. One-sided tooth-like tooth portion formed by alternately arranging the two-sided swing teeth 22b.
22 and, at the other end, a handle 23 having a plurality of mounting holes 23a for mounting to a chucking portion of a swing sawing device (not shown). This surgical saw
In the case of 20, the tooth portion 22 has the one-sided swing tooth shape as described above, and therefore when used in combination with the guide member 10 described later, even if the runout tooth 22b is damaged or deformed, As long as it is used so as not to face the resection plane, the bone resection will not cause an error.

In this embodiment, the saw blade 20 and the guide member 10 are made of stainless steel, but other hard metals can be used. However, in view of rust resistance and economy, stainless steel is preferable.

Next, a stainless aiming guide member 10 of this embodiment is shown in FIG.
In order to insert 0 and guide it, two guide slits 11 sandwiched between two guide pieces arranged in parallel are provided at left and right symmetrical positions.

The guide slit 11 is composed of a main body slit 11a and a tooth slit 11b which are continuous with each other.
Of these, a pair of parallel guide surfaces 12a is provided above and below the main body slit 11a, and the distance between the guide surfaces 12a is the gap s _{1 of the} guide slit 11. Further, the tooth slit 11b is formed on the guide surface 12 of the guide piece 12 located on the upper side.
It has a step portion 13 formed on the side of a in contact with the bone.

The thickness of the tooth slit 11b is set so that the tooth 22 can be accommodated in the tooth runout width t ₂ of the runout tooth 22a of the tooth 22.
Slightly larger than. Therefore, even when the guide portion 10 is brought into contact with the bone to be excised, the saw cutting 20 is inserted into the guide slit 11 from the side surface of the guide member 10, and the tooth portion 22 is swung in the tooth portion slit 11b. By doing so, the bone resection can be started. Therefore, the guide slit 11
Gap s ₁ is not be greater than the tooth amplitude t ₂ of the deflection teeth 22a of the teeth 22, the thickness t ₁ of the body portion 21 as the main body portion 21 of the saw cut 20 is swingably Slightly larger than the above.

As shown in FIG. 4, the saw blade 20 may be formed by forming two step portions 13 on the contact sides of the upper and lower guide pieces 12 with both bones. It is also possible to guide the saw blade 20 with toothed teeth 22.

In addition, the guide member 10 has a mounting portion 14 which is fitted and locked to the installation jig 30 on the upper side, and a wire hole portion 15 having a wire hole 15a through which the Kirschner wire 40 is inserted on the lower side.

Now, the thickness t ₁ of the main body portion 21 of the saw blade 20 made of stainless steel according to the present embodiment is determined by the runout teeth 22b of the tooth portion 22 and the horizontal teeth 22a.
With a runout width t _{2 of} 1.3 mm and 0.3 mm less 1 mm,
Gap of guide slit 11 of stainless steel guide member 10
S ₁ is 0.1 mm larger than the thickness t ₁ of the main body portion 21 of the saw blade 20 by 1.1 mm, and the gap between the tooth slits 11b is t between the run tooth 22b of the run tooth portion 22 of the saw blade 20 and the horizontal tooth 22a. 1 mm larger than _{2 and} 1.4 mm, and the length l ₁ of the body slit 11a is 1
Although the length l ₂ of the tooth slit 11b is 0 mm, the maximum deflection angle of the saw cutting 20 when the bone cutting is performed using the saw cutting 20 of the present invention and the guide member 10 in combination is theoretically 0 mm. It is derived from the following formula.

[0021]

[Equation 1]

On the other hand, as shown in FIG. 5, the runout width t ₂ of the runout teeth 22b is 1.6 mm, and the thickness t ₁ of the main body portion 21 is 1.0 mm, which is the same as the saw 20 of the present invention. Off 20, figure
When used in combination with the conventional guide member 10 having a gap s ₂ of the guide slit 11 of 1.8 mm and a length l ₃ of 15 mm as shown in 6, the maximum deflection angle of the saw blade 20 is calculated by the following formula. Can be led to.

[0023]

[Equation 2]

Now, using the surgical saw 20 of the present invention and the aiming guide portion 10 and using the instrument as shown in FIG. 1, the proximal end portion of the tibia 50 for total knee arthroplasty is resected 10. As an example, the error was 0.5 ° at maximum and 0.3 ° on average. From the above, it has been proved that, when the surgical saw 20 of the present invention and the aiming guide member 10 are used in combination, the bone resection that is clearly more accurate than the conventional one can be performed.

[0025]

[Effect] When the surgical saw blade and the aiming guide member of the present invention are used, there is no error due to damage or wear of the runout teeth of the saw blade, and in addition, the deflection angle of the saw blade is almost generated. Since there is no such thing, it is possible to perform bone resection at a more accurate angle, and it is possible to perform bone resection that is particularly accurate compared to the conventional one.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention, FIG.
(B) are from different angles.

2A and 2B are views showing a surgical saw blade 20 of the present invention, in which FIG. 2A is a top view and FIG. 2B is a side view.

3A and 3B are views showing an aiming guide member 10 according to an embodiment of the present invention, in which FIG. 3A is a side view and FIG. 3B is a front view.

4A and 4B are views showing one embodiment of the aiming guide member 10 of the present invention, wherein FIG. 4A is a side view and FIG. 4B is a front view.

5A and 5B are views showing a conventional surgical saw blade 20, where FIG. 5A is a top view and FIG. 5B is a side view.

FIG. 6 is a view showing a conventional aiming guide member 10,
(A) is a front view and (b) is a side view.

[Explanation of symbols]

10: Guide member 20: Saw cutting 30: Installation tool 40: Kirschner wire 50: Tibia 60: Oscillating saw cutting device 11: Guide slit 12: Guide piece 12a: Guide surface 13: Step portion 14: Mounting portion 15: Wire hole Part 21: Body part 22: Tooth part 23: Handle s: Gap between guide slits t ₁ : Body part thickness t ₂ : Deflection width l: Length

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoichi Taneda             4-4-1 Swan, Togo, Aichi-gun, Aichi Prefecture (72) Inventor Futaka Iguchi             2-30-2 Shimomizo-cho, Showa-ku, Nagoya-shi

Claims (2)

[Claims] 1. A surgical saw blade for use with an aiming guide member having two parallel guide pieces, wherein the tip of the saw blade has a tooth oriented in the longitudinal direction and a predetermined spread angle with respect to the longitudinal direction. A saw blade for surgery, characterized in that a tooth portion is formed by alternately forming a plurality of teeth each having a tooth. 2. A sighting guide member for guiding a surgical saw having two guide pieces arranged in parallel, wherein a step portion is formed on at least one guide surface of the guide pieces on the side in contact with the bone. A guide member for sighting.