Surgical cutting bar

Abstract

To provide a surgical cutting bar with further high cutting force.SOLUTION: A surgical cutting bar comprises a shaft part rotating around a rotation axis, and a cutting part formed at a tip end of the shaft part. The cutting part includes a plurality of grooves spirally extending from the tip end to a rear end of the shaft part, where the plurality of grooves are respectively spaced apart in the rotation direction and corrugated peripheral cutting edges with recesses and protrusions recessing / protruding in a direction perpendicular to the rotation axis are spirally formed at positions clamped between the adjacent grooves. In the corrugated peripheral cutting edge, the protrusions of each corrugated peripheral cutting edge may be configured to be shifted in the axial direction with respect to a protrusion of the corrugated peripheral cutting edge, adjacent in the rotating direction.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a surgical cutting bar, which is a medical instrument for surgical operations.

Background Art

[0002] Conventionally, there has been a surgical bar as a means for cutting bone, which is attached to a handpiece that is rotationally driven by a motor or a turbine to cut bone. The surgical cutting bar includes a shaft portion that rotates about a rotation axis and a cutting portion provided at the tip of the shaft portion. By attaching the shaft portion to a portion that becomes the rotational output of the handpiece, such a surgical cutting bar can rotationally cut a cutting target such as bone. (Patent Document 1)

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the medical field where surgeries are performed using surgical cutting bars, measures to reduce the burden on patients are required. One measure to reduce the burden on patients is to shorten the surgical time. Against this background, regarding the performance required of surgical cutting bars, high cutting force leading to a shortening of the surgical time is required, and there is a problem in realizing this.

[0005] The present invention solves the above problems and aims to provide a surgical cutting bar with higher cutting force.

Means for Solving the Problems

[0006] In order to solve the problem, a surgical cutting bar is provided, which includes a shaft portion that rotates about a rotation axis and a cutting portion formed on the tip side of the shaft portion. The cutting portion includes a plurality of grooves that extend spirally from the tip side to the rear end side of the shaft portion. The plurality of grooves are arranged at intervals in the rotation direction, and at positions sandwiched between adjacent grooves, there are provided a concave portion and a convex portion that are concave and convex in a direction perpendicular to the rotation axis. Type The outer peripheral blade is formed in a spiral shape, Recessed part and The convex portion has a curved shape. In the waveform outer peripheral blade, the convex portions of the respective waveform outer peripheral blades may be configured to be offset in the axial direction with respect to the convex portions of the waveform outer peripheral blades adjacent in the rotation direction.

Advantages of the Invention

[0007] According to the present invention, it is possible to provide a surgical cutting bar with higher cutting force.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0009] (Embodiment) Hereinafter, embodiments will be described with reference to the drawings. Here, as a medical device using the surgical cutting bar 200 according to the present invention, a surgical system 100, which is an orthopedic surgical instrument, will be exemplified.

[0010] <Surgical System> FIG. 1 is a configuration diagram of a surgical system 100. The surgical operation system 100 includes a control unit 101, a handpiece 103, a connection cable 105 connecting the handpiece 103 to the control unit 101, and a foot switch 107.

[0011] The handpiece 103 has a housing with a rod-shaped outer shell and is provided with an attachment 103a on the tip side. A surgical cutting bar 200 is detachably attached to the attachment 103a of the handpiece 103. Also, inside the handpiece 103, a power source such as an air motor or an electric motor (electric motor) for rotationally driving the surgical cutting bar 200 is provided. The power source is rotated or stopped by a foot switch 107 connected to the control unit 101. The control unit 101 controls the rotational drive of the handpiece 103.

[0012] The handpiece 103 is used by a doctor performing a surgical operation gripping the grip portion 103b and directly operating to bring the rotating surgical cutting bar 200 into contact with the affected part that becomes the cutting position. In addition, a hand switch for manual operation may be provided on the handpiece 103 to rotate or stop the drive source of the handpiece 103, and the operation of this hand switch may be performed. Also, the handpiece 103 may be other than that used in the description of this embodiment as long as it imparts an appropriate rotational driving force to the surgical cutting bar 200.

[0013] <Surgical cutting bar> Next, with reference to FIGS. 2 to 6, the configuration of the surgical cutting bar 200 will be described. FIG. 2 is a side view of the surgical cutting bar 200, and is a plan view seen from the radial direction in a state where the tip of the surgical cutting bar 200 faces downward. FIG. 3 is an enlarged perspective view of the cutting portion 220 of the surgical cutting bar 200. FIG. 4 is a cross-sectional view taken at the position A-A of FIG. 2. FIG. 5 is a cross-sectional view of each corrugated outer peripheral blade 240 (241, 242, 243). In FIG. 5, in order to clearly show the configuration of each corrugated outer peripheral blade and the relationship between adjacent corrugated outer peripheral blades, it is a schematic cross-sectional view obtained by cutting each corrugated outer peripheral blade extending spirally from the tip to the rear end along the spiral. FIG. 6 is a schematic view of the cutting portion 220, and is a plan view seen from the radial direction in a state where the tip of the surgical cutting bar 200 faces downward.

[0014] In addition, the line O shown in the figure is a rotation axis indicating the rotation center of the surgical cutting bar 200. That is, the direction in which the rotation axis O extends is the axial direction. Further, the direction perpendicular to the rotation axis O is defined as the radial direction. Also, the arrow R shown in the figure indicates the rotation direction of the surgical cutting bar 200.

[0015] The surgical cutting bar 200 is a rod-shaped member formed of a hard material such as stainless steel or cemented carbide (tungsten carbide). Such a surgical cutting bar 200 includes a shaft portion 210 that rotates about the rotation axis O and a cutting portion 220 formed on the tip side of the shaft portion 210. A connecting portion 211 is provided at the rear end of the shaft portion 210 on the side opposite to the cutting portion 220, and is connected and fixed to a rotating shaft located inside the attachment 103a of the handpiece 103. The surgical cutting bar 200 fixed to the rotating shaft of the attachment 103a rotates about the rotation axis O with the cutting portion 220 and the shaft portion 210 by the rotational drive of the handpiece 103.

[0016] In the surgical system 100 to which the surgical cutting bar 200 is attached, the operator rotates the surgical cutting bar 200 by operating the foot switch 107 while holding the handpiece 103. Then, with the cutting part 220 of the surgical cutting bar 200 rotated, the operator presses it against the object to be resected, such as bone, and appropriately moves the handpiece 103 to perform a treatment for cutting the object to be resected. In addition, in the case of this embodiment, the rotation direction R of the surgical cutting bar 200 is clockwise when viewed from the user holding the handpiece 103.

[0017] <Configuration of the cutting part> In the following description, in the surgical cutting bar 200, based on the axial direction which is the direction in which the rotation axis O extends, the direction orthogonal to the axial direction is the radial direction, the side where the cutting part 220 is located is the tip side, and the side where the connecting part 211 is located is the rear end side. In addition, the same reference numerals are given to the same members or the same parts to omit or simplify the description thereof.

[0018] Referring to FIGS. 2 to 4, the cutting part 220 includes a groove 230 that spirally extends from the tip side to the rear end side of the shaft part 210. In the case of this embodiment, there are three grooves 230, which are the first groove 231, the second groove 232, and the third groove 233, respectively. These first groove 231, second groove 232, and third groove 233 are each arranged in a spiral shape at intervals in the rotation direction without intersecting each other.

[0019] In addition, on the ridge part formed at a position sandwiched between adjacent grooves 230 (231, 232, 233), a corrugated outer peripheral blade 240 that is concave and convex in the radial direction, which is the direction perpendicular to the rotation axis, is formed. Since the corrugated outer peripheral blade 240 is formed along the adjacent grooves 230, it spirally extends from the tip side to the rear end side along the axial direction. That is, the cutting part 220 is a part including the corrugated outer peripheral blade 240 formed by the continuous grooves 230 and the concave and convex parts in the radial direction.

[0020] In the case of this embodiment, the corrugated outer peripheral blade 240 formed on the cutting portion 220 includes a first corrugated outer peripheral blade 241 formed at a position sandwiched between the first groove 231 and the second groove 232, a second corrugated outer peripheral blade 242 formed at a position sandwiched between the second groove 232 and the third groove 233, and a third corrugated outer peripheral blade 243 formed at a position sandwiched between the third groove 233 and the first groove 231.

[0021] Referring to FIG. 5, each corrugated outer peripheral blade 240 (241, 242, 243) will be described. In FIG. 5, a schematic cross-sectional view of the first corrugated outer peripheral blade 241, a schematic cross-sectional view of the second corrugated outer peripheral blade 242, and a schematic cross-sectional view of the third corrugated outer peripheral blade 243 are shown. Also, the tip of the first corrugated outer peripheral blade 241 is referred to as tip 241c, the tip of the second corrugated outer peripheral blade 242 is referred to as tip 242c, and the tip of the third corrugated outer peripheral blade 243 is referred to as tip 243c. The positions of the respective tips 241c, 242c, 243c in the rotational direction R are shown aligned.

[0022] In the first corrugated outer peripheral blade 241, the portion that is convex in the radial direction is the first corrugated outer peripheral blade convex portion 241a, and the portion that is concave in the radial direction is the first corrugated outer peripheral blade concave portion 241b. This first corrugated outer peripheral blade convex portion 241a is a portion including a peak that protrudes in the radial direction. Also, the first corrugated outer peripheral blade concave portion 241b is a portion that becomes the bottom that is concave in the radial direction.

[0023] Similarly, in the second corrugated outer peripheral blade 242, the portion that is convex in the radial direction is the second corrugated outer peripheral blade convex portion 242a, and the portion that is concave in the radial direction is the second corrugated outer peripheral blade concave portion 242b. Also, in the third corrugated outer peripheral blade 243, the portion that is convex in the radial direction is the third corrugated outer peripheral blade convex portion 243a, and the portion that is concave in the radial direction is the third corrugated outer peripheral blade concave portion 243b. The shapes of the concave and convex portions of these first corrugated outer peripheral blade 241, second corrugated outer peripheral blade 242, and third corrugated outer peripheral blade 243 are generally the same shape.

[0024] Next, the structures of the first corrugated outer peripheral blade 241, second corrugated outer peripheral blade 242, and third corrugated outer peripheral blade 243 and the positional relationships of their respective parts will be described. In the shape on the radially outer side of the first corrugated outer peripheral blade 241, from the tip 241c of the first corrugated outer peripheral blade 241 to the portion where the shape of the first corrugated outer peripheral blade recess 241b starts to be formed, it becomes the first straight portion 241d having a linear shape. That is, in the shape on the radially outer side of the first corrugated outer peripheral blade 241, the first straight portion 241d extending from the tip 241c is located, and from this first straight portion 241d toward the rear end side, the first corrugated outer peripheral blade recess 241b and the first corrugated outer peripheral blade convex portion 241a are alternately formed, resulting in a concavo-convex shape.

[0025] Also, in the shape on the radially outer side of the second corrugated outer peripheral blade 242, from the tip 242c of the second corrugated outer peripheral blade 242 to the portion where the shape of the second corrugated outer peripheral blade recess 242b starts to be formed, it becomes the second straight portion 242d having a linear shape. That is, in the shape on the radially outer side of the second corrugated outer peripheral blade 242, the second straight portion 242d extending from the tip 242c is located, and from this second straight portion 242d toward the rear end side, the second corrugated outer peripheral blade recess 242b and the second corrugated outer peripheral blade convex portion 242b are alternately formed, resulting in a concavo-convex shape.

[0026] Similarly, in the shape on the radially outer side of the third corrugated outer peripheral blade 243, from the tip 243c of the third corrugated outer peripheral blade 243 to the portion where the shape of the third corrugated outer peripheral blade recess 243b starts to be formed, it becomes the third straight portion 243d having a linear shape. That is, in the shape on the radially outer side of the third corrugated outer peripheral blade 243, the third straight portion 243d extending from the tip 243c is located, and from this third straight portion 243d toward the rear end side, the third corrugated outer peripheral blade recess 243b and the third corrugated outer peripheral blade convex portion 243a are alternately formed, resulting in a concavo-convex shape.

[0027] Here, the size Δ241d of the first straight portion 241d is configured to be shorter than the size Δ242d of the second straight portion 242d. Also, the size Δ242d of the second straight portion 242d is configured to be shorter than the size Δ243d of the third straight portion 243d. That is, the sizes of the respective straight portions are configured to be different, and the relationship between the sizes of Δ241d, Δ242d, and Δ243d is Δ241d < Δ242d < Δ243d.

[0028] Also, in the case of this embodiment, for example, in the case of the first waveform outer peripheral blade 241, if the distance between the peak positions of the adjacent first waveform outer peripheral blade convex portions 241a is L, then Δ242d - Δ241d = L / 3. That is, Δ242d is configured to be L / 3 longer than Δ241d. Since it is configured in this way, the second waveform outer peripheral blade 242, compared with the first waveform outer peripheral blade 241, has a position where the first second waveform outer peripheral blade concave portion 242b on the tip side is formed shifted by L / 3 toward the rear end side. Along with this, the series of the second waveform outer peripheral blade convex portions 242a and the second waveform outer peripheral blade concave portions 242b following from the first second waveform outer peripheral blade concave portion 242b on the tip side to the rear end side is also shifted by L / 3 toward the rear end side with respect to the first waveform outer peripheral blade 241.

[0029] Similarly, Δ243d - Δ242d = L / 3. That is, Δ243d is configured to be L / 3 longer than Δ242d. Since it is configured in this way, the third waveform outer peripheral blade 243, compared with the second waveform outer peripheral blade 242, has a position where the first third waveform outer peripheral blade concave portion 243b on the tip side is formed shifted by L / 3 toward the rear end side. Along with this, the series of the third waveform outer peripheral blade convex portions 243a and the third waveform outer peripheral blade concave portions 243b following from the first third waveform outer peripheral blade concave portion 243b on the tip side to the rear end side is also shifted by L / 3 toward the rear end side with respect to the second waveform outer peripheral blade 242.

[0030] Since the cutting portion 220 is configured in this way, in the waveform outer peripheral blades 240 (241, 242, 243), the convex portions (241a, 242a, 243a) of the respective waveform outer peripheral blades 240 (241, 242, 243) are in positions shifted in the axial direction with respect to the convex portions (241a, 242a, 243a) of the adjacent waveform outer peripheral blades 240 (241, 242, 243) in the rotational direction. That is, in the case of this embodiment, with respect to the peak position of the first waveform outer peripheral blade convex portion 241a of the first waveform outer peripheral blade 241, the peak position of the second waveform outer peripheral blade convex portion 242a of the second waveform outer peripheral blade 242 is in a position shifted by L / 3 toward the rear end side in the axial direction.

[0031] Similarly, with respect to the peak position of the second waveform outer peripheral blade convex portion 242a of the second waveform outer peripheral blade 242, the peak position of the third waveform outer peripheral blade convex portion 243a of the second waveform outer peripheral blade 243 is shifted by L / 3 toward the axially rear end side. As a result, the peak positions of the first waveform outer peripheral blade convex portion 241a, the second waveform outer peripheral blade convex portion 242a, and the third waveform outer peripheral blade convex portion 243a are in a positional relationship where they do not overlap in the rotational direction.

[0032] Since the cutting portion 220 is configured as described above, it is possible to provide a surgical cutting bar 200 that has a higher cutting force capable of reducing the burden associated with cutting and efficiently performing cutting on the bone to be cut. Specifically, in the cutting portion 220, by shifting the peak positions of the first waveform outer peripheral blade convex portion 241a, the second waveform outer peripheral blade convex portion 242a, and the third waveform outer peripheral blade convex portion 243a in the axial direction, they are in a positional relationship where they do not overlap in the rotational direction.

[0033] In the present embodiment, since there are three waveform outer peripheral blades 240, the peak positions of the respective outer peripheral blade convex portions are configured to be shifted by L / 3. When there are four waveform outer peripheral blades 240, the peak positions of the respective outer peripheral blade convex portions are configured to be shifted by L / 4. That is, when there are N waveform outer peripheral blades 240, the peak positions of the respective outer peripheral blade convex portions are configured to be shifted by L / N.

[0034] When the cutting portion 220 cuts the bone to be cut, the peaks of the respective waveform outer peripheral blade convex portions that come into contact with the cutting object can be shifted in the axial direction, and the cutting force acting on the cutting object can be dispersed partially. As a result, when cutting a bone or the like, it is difficult for a large force to be applied all at once partially, and it can be cut efficiently in a dispersed manner. By configuring it like the cutting portion 220, particularly when cutting a human bone, the influence associated with cutting on the bone to be cut can be reduced.

[0035] In addition, in the present embodiment, the sizes of the first straight portion 241d, the second straight portion 242d, and the third straight portion 243d are made different so that the position where the corrugated outer peripheral blade is formed is shifted in the axial direction. As a result, the peak positions of the first corrugated outer peripheral blade convex portion 241a, the second corrugated outer peripheral blade convex portion 242a, and the third corrugated outer peripheral blade convex portion 243a are in a positional relationship where they do not overlap in the rotational direction.

[0036] In this way, by appropriately changing the sizes of the respective straight portions, during the machining operation for forming the cutting portion 220, it is possible to easily perform machining to shift the peak positions of the respective outer peripheral blade convex portions. Further, when inspecting the quality of the surgical cutting bar 200, by measuring the sizes of the straight portions, it is possible to easily measure whether or not the shape of the cutting portion 220 is accurately formed.

[0037] Furthermore, in the corrugated outer peripheral blade 240 (241, 242, 243) of the present embodiment, the first corrugated outer peripheral blade convex portion 241a, the second corrugated outer peripheral blade convex portion 242a, and the third corrugated outer peripheral blade convex portion 243a, which are all convex portions, and the first corrugated outer peripheral blade concave portion 241b, the second corrugated outer peripheral blade concave portion 242b, and the third corrugated outer peripheral blade concave portion 243b, which are all concave portions, are cutting edges for cutting the object to be cut. That is, the entire spiral corrugated outer peripheral blade 240 (241, 242, 243) formed by the curves forming the concave and convex portions serves as a cutting edge capable of cutting the object to be cut.

[0038] Since the cutting portion 220 is configured in this way, even if the cutting portion 220 contacts the object to be cut from any direction, the cutting portion 220 can perform cutting. That is, since the curves forming the concave and convex portions all serve as cutting edges, the cutting edges are always in contact with the object to be cut. As a result, even if the cutting portion 220 contacts the object to be cut in various directions and angles, it is possible to perform cutting.

[0039] The surgical cutting bar 200 is such that the attached handpiece 103 is manually operated by a doctor, and the cutting part 220 contacts the affected part to be cut at various orientations and angles for use. Thus configured as described above, it is effective in shortening the operation time and reducing the burden on the patient. In particular, since the corrugated outer peripheral blade 240 (241, 242, 243) has a concavo-convex curved shape, the amount of contact between the corrugated outer peripheral blade 240 and the object to be cut at one time during cutting can be reduced, and the cutting resistance during cutting can be reduced. Thereby, the cutting resistance can be reduced and the burden on the affected part during cutting can be reduced.

[0040] Next, with reference to FIG. 6, the twist angle of the corrugated outer peripheral blade 240 (241, 242, 243) will be described. The twist angle is the angle formed between the rotation axis O of the surgical cutting bar 200 and the corrugated outer peripheral blade 240 (241, 242, 243) formed in a helically twisted manner. In the figure, the relationship between the corrugated outer peripheral blade 240 and the rotation axis O is schematically shown. Also, when the surgical cutting bar 200 is viewed from the radial direction, the angles formed between the corrugated outer peripheral blade 240 and the rotation axis O are denoted as θ1, θ2, and θ3 from the tip side.

[0041] The rotation direction R of the surgical cutting bar 200 is clockwise. The corrugated outer peripheral blade 240 is formed in a spiral along the circumference of the rotation axis O of the surgical cutting bar 200. Also, the cutting edge of the corrugated outer peripheral blade 240 for cutting the object to be cut faces the right direction, which is the same as the rotation direction R. And the corrugated outer peripheral blade 240 is configured such that the twist angle at the position on the rear end side is larger than that on the tip side. That is, the angles formed between the corrugated outer peripheral blade 240 and the rotation axis O have the following relationship. θ1 < θ2 < θ3

[0042] In this way, by configuring the corrugated outer peripheral blade 240 such that the twist angle at the position on the rear end side is larger than that on the tip side, the strength of the cutting part 220 of the surgical cutting bar 200 can be improved. In particular, by increasing the twist angle on the rear end side of the corrugated outer peripheral blade 240, the strength can be improved. In addition, by reducing the twist angle on the tip side of the corrugated outer peripheral blade 240, the tip can form a cutting portion 220 that takes advantage of the flexibility of the metal. As a result, the surgical cutting bar 200 can perform delicate cutting operations on the flexible tip side while improving the strength.

[0043] Next, referring to FIGS. 3 and 6, in the cutting portion 220 of the surgical cutting bar 200, the corrugated outer peripheral blades 240 (241, 242, 243) face in the same direction as the rotation direction R and are twisted in the direction opposite to the rotation direction R. In the surgical cutting bar 200 of the present embodiment, since the rotation direction R of the surgical cutting bar 200 is clockwise, the corrugated outer peripheral blades 240 (241, 242, 243) face rightward. That is, when the surgical cutting bar 200 rotates clockwise, the corrugated outer peripheral blades 240 (241, 242, 243) face the cutting target. And the corrugated outer peripheral blades 240 (241, 242, 243) are twisted counterclockwise and formed in a spiral shape.

[0044] The surgical cutting bar 200 of the present embodiment is a so-called right blade left twist. When looking at the tip of the surgical cutting bar 200 downward from the radial direction, the spiral part slopes upward to the left. Since the surgical cutting bar 200 has a cutting portion 220 with a right blade left twist in this way, when cutting the cutting target, a force acts from the tip side toward the rear end. That is, a force acts in the direction of pushing the surgical cutting bar 200 against the attachment 103a of the handpiece 103 to which the surgical cutting bar 200 is attached. Therefore, when cutting the affected part of the patient, it is possible to prevent the surgical cutting bar 200 from falling off to the patient side.

[0045] Next, referring to FIG. 6, the cutting portion 220 of the surgical cutting bar 200 is configured in a tapered shape that widens from the tip side to the rear end side. That is, the cutting portion 220 has a shape in which the diameter gradually increases from the tip side to the rear end side. In this way, by narrowing the diameter of the tip side of the cutting portion 220, the cutting portion of the affected area can be reduced, thereby reducing the burden on the patient. At the same time, by increasing the diameter of the rear end side, the strength capable of withstanding cutting can be realized.

Explanation of Signs

[0046] O Axis of rotation R Rotation direction of the surgical cutting bar 100 Surgical system 101 Control unit 103 Handpiece 103a Attachment 103b Gripping portion 105 Connection cable 107 Foot switch 200 Surgical cutting bar 210 Shaft portion 211 Connection portion 220 Cutting portion 230 Groove 231 First groove 232 Second groove 233 Third groove 240 Wavy outer peripheral blade 241 First wavy outer peripheral blade 242 Second wavy outer peripheral blade 243 Third wavy outer peripheral blade

Claims

1. A surgical cutting bar comprising a shaft portion that rotates about a rotation axis and a cutting portion formed on the tip side of the shaft portion, The cutting portion includes a plurality of grooves extending spirally from the tip side to the rear end side of the shaft portion, and the plurality of grooves are arranged at intervals in the rotation direction. At positions sandwiched between adjacent grooves, a corrugated outer peripheral blade having concave and convex portions that are concave and convex in a direction perpendicular to the rotation axis is formed spirally. The concave and convex portions have a curved shape, In the corrugated outer peripheral blade, the convex portions of each corrugated outer peripheral blade are located at positions axially displaced with respect to the convex portions of the corrugated outer peripheral blades adjacent in the rotation direction. A surgical cutting bar characterized by this.

2. The surgical cutting bar according to claim 1, wherein the corrugated outer peripheral blade in a spiral shape has a larger twist angle at a position on the rear end side than on the tip side.

3. The surgical cutting bar according to claim 1, wherein in the cutting portion, the corrugated outer peripheral blade faces in the rotation direction and is twisted in a direction opposite to the rotation direction.

4. The surgical cutting bar according to claim 1, wherein the cutting portion has a tapered shape that widens from the tip side to the rear end side.

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