Creator

Abstract

Provided is a retractor that can form a space in a joint cavity for a field of view through an endoscope and for treatment in a state where a wound area is open. The retractor is provided with first arm parts 2, 3, and a second arm part 4 positioned between the first arm parts 2, 3. The first arm parts 2, 3 are provided with first claw sections 12, 13 hung on a wound area entrance edge. The second arm part 4 is provided with a second claw section 14 hung on the wound area entrance edge. When the first arm parts 2 ,3 and the second arm part 4 are in closed states, the first claw sections 12, 13 and the second claw section 14 overlap each other.

Description

[Technical Field]

[0001] The present invention relates to a retractor that abuts against the edges of an incised wound in skin tissue to open the wound. [Background technology]

[0002] In recent years, arthroscopic surgery using an arthroscope has been performed as an orthopedic treatment for patients with intra-articular lesions. Arthroscopic surgery has become widespread in the field of orthopedics, with the aim of reducing the physical burden on patients and speeding up post-operative recovery. In arthroscopic surgery, specialized surgical instruments and an endoscope are inserted into a relatively small incision made in the surface skin of the knee or elbow to treat the lesion.

[0003] In arthroscopic surgery, the surgeon performs the procedure using surgical instruments inserted into the joint cavity while checking the endoscopic image on a monitor screen. It is essential to ensure a clear view of the endoscope and sufficient space within the joint cavity (hereafter referred to as the workspace) for the procedure. Furthermore, a retractor is used to keep the wound open, allowing for smooth insertion of surgical instruments and the endoscope into the wound.

[0004] Conventionally, a forceps-like retractor has been known that has a pair of tip portions with claw portions that hook onto the edges of the wound and an operating grip portion for opening and closing the tip portions (see Patent Document 1 below).

[0005] In this retractor (forceps-type retractor), the claws at the tip that are inserted into the wound are shaped so that they overlap each other in tandem when closed, making it easier to insert them into the wound opening.

[0006] Another known forceps-type retractor has a plurality of claws at each tip (see Patent Document 2 below).

[0007] This retractor comprises a pair of operating grips, a pivot that rotatably connects the operating grips, and a pair of arms that extend on opposite sides of each operating grip via the pivot, with multiple claws provided at the tips of the arms.

[0008] The multiple claws protrude perpendicular to the extension direction of the arm and are spaced apart from one another in the extension direction of the arm. By providing multiple claws in this manner, each claw abuts at a different position on the edge of the wound, preventing the wound from remaining closed and extending in a straight line, allowing the wound to be opened. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-27933 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-182197 Summary of the Invention [Problem to be solved by the invention]

[0010] However, with the wound retractor described in Patent Document 1, when the two claw portions are hooked onto the edges of the wound and the wound is moved apart to widen the wound, the wound extends in a straight line while remaining almost closed, and the wound cannot be opened widely.

[0011] Furthermore, although the retractors described in Patent Document 1 can be used to open a square wound by using two of them, they do not take into consideration the need to secure a workspace during arthroscopic surgery, which results in poor workability during arthroscopic surgery.

[0012] In addition, in the device described in Patent Document 2, the claws protrude perpendicular to the direction in which the arms extend, so when the claws are inserted deeply into the wound, the arms get in the way and the claws do not hook shallowly onto the wound edge, which makes it easier for the claws to release their grip on the wound edge.

[0013] As described above, the device described in Patent Document 2 does not take into consideration the securing of workspace during arthroscopic surgery, and has the disadvantage of poor workability during arthroscopic surgery.

[0014] In view of the above, an object of the present invention is to provide a retractor that can easily form a workspace for arthroscopic surgery while keeping the wound open. [Means for solving the problem]

[0015] In order to achieve this object, the first invention provides a retractor that opens an incised skin tissue wound by contacting the wound edge, the retractor comprising: a pair of first arms integrally connected to each other at the base end and extending toward the tip; a single second arm located between the first arms, rotatably connected to the first arm via a shaft at the base end and extending toward the tip; a closed state in which the first and second arms overlap each other; and a closed state in which the first and second arms are spaced apart at the tip end. and an operating unit for opening and closing the first arm and the second arm, with a closed state being an open state, and the first arm has a first claw portion at its tip that protrudes in the opening direction to hook onto the edge of the wound, and the second arm has a second claw portion at its tip that protrudes in the opposite direction to the first claw portion to hook onto the edge of the wound, and when the first arm and the second arm are in a closed state, the first claw portion and the second claw portion overlap each other.

[0016] The retractor of the first invention is provided with three claw portions: two first claw portions provided at the tip ends of two first arms, and one second claw portion provided at the tip end of one second arm.

[0017] In the closed state, the second claw portion is housed between the two first claw portions, so that the three claw portions are gathered together in a relatively small size at the tips of the first and second arms, allowing for smooth insertion into the wound in the incised skin tissue.

[0018] When the first and second arms begin to open from their closed positions by operating the operating unit, the first and second claws latch onto the wound edge at their respective positions. Since each arm has a claw at its tip, the arms do not get in the way of the claws latching onto them. Furthermore, because each claw protrudes in the direction the arms open, they latch onto the wound edge relatively deeply.

[0019] When the first and second arms are opened, the first and second claws move away from each other in opposite directions, widening the wound. At this time, the two first claws and one second claw are in contact with the edge of the wound at three points, preventing the wound from remaining closed and extending linearly, and allowing the wound to be opened to a sufficient width.

[0020] Furthermore, as described above, because the hooks of the claws hook relatively deeply into the wound edge, simply lifting the retractor can reliably lift the skin tissue around the wound, ensuring a sufficient workspace. This makes the retractor of the present invention suitable for use in forming a workspace in arthroscopic surgery using an arthroscope in orthopedic treatment.

[0021] In the first invention described above, when the overlapping direction of the first claw portion and the second claw portion in the closed state is the thickness direction of each of the first claw portion and the second claw portion, it is preferable that the first claw portion has a smaller thickness dimension than the second claw portion.

[0022] For example, when the total thickness of the pair of first claw portions and the second claw portion is L, rather than making the thicknesses of the pair of first claw portions and the second claw portions equal to "L / 3", it is better to make the thickness of each of the pair of first claw portions "L / 4" and the thickness of the second claw portion "L / 2", as this will allow the wound to be opened more widely in the open state.

[0023] The second invention relates to a wound retractor that opens a wound by contacting an edge of an incised skin tissue, the wound retractor comprising: a plurality of first arms integrally connected to one another at the base end and extending toward the tip; and a plurality of second arms integrally connected to one another at the base end and arranged alternately with the first arms, and whose base ends are rotatably connected to the first arms via shafts and extend toward the tip; a closed state in which the first arms and the second arms overlap, and a closed state in which the tip ends of the first arms and the second arms are separated from each other. and an operating unit for operating the first arm and the second arm to open and close, with a closed state being an open state, wherein the first arm has a first claw portion at its tip that protrudes in the opening direction to hook onto the edge of the wound, and the second arm has a second claw portion at its tip that protrudes in the opposite direction to the first claw portion to hook onto the edge of the wound, and when the first arm and the second arm are in a closed state, the first claw portion and the second claw portion overlap each other.

[0024] The retractor of the second invention is provided with four or more claw portions, including two or more first claw portions provided at the tip of each of two or more first arms and two or more second claw portions provided at the tip of each of two or more second arms.

[0025] In the closed state, the first claw portions and the second claw portions alternately overlap each other, allowing for smooth insertion into the wound in the incised skin tissue.

[0026] When the first and second arms begin to open from their closed positions by operating the operating unit, the first and second claws latch onto the wound edge at their respective positions. Since each arm has a claw at its tip, the arms do not get in the way of the claws latching onto them. Furthermore, because each claw protrudes in the direction the arms open, they latch onto the wound edge relatively deeply.

[0027] When the first and second arms are opened, the first and second claws move away from each other in opposite directions, widening the wound. At this time, the first and second claws are in contact with the edges of the wound at their respective positions, preventing the wound from remaining closed and extending linearly, and allowing the wound to be opened to a sufficient width.

[0028] Furthermore, as described above, because the hooks of the claws hook relatively deeply into the wound edge, simply lifting the retractor can reliably lift the skin tissue around the wound, ensuring a sufficient workspace. This makes the retractor of the present invention suitable for use in forming a workspace in arthroscopic surgery using an arthroscope in orthopedic treatment.

[0029] In the second invention, when the overlapping direction of the first claw portion and the second claw portion in the closed state is defined as the thickness direction of each of the first claw portion and the second claw portion, it is preferable that at least a pair of claw portions located on the outermost sides of the first claw portion and the second claw portion have a thickness dimension smaller than that of the other claw portions.

[0030] For example, if the total thickness of a pair of first claw portions and a pair of second claw portions in the overlapping direction is L, rather than making each thickness equal to "L / 4," making the thickness of the pair of outermost claw portions "L / 6" and the thickness of the pair of inner claw portions "L / 3" will allow the wound to be opened more widely when the first arm portion and the second arm portion are opened.

[0031] In addition, in the first or second invention, it is preferable that the tip of the first claw portion and the tip of the second claw portion each face toward the base end when the first arm portion and the second arm portion are in an open state compared to when they are in a closed state.

[0032] This ensures that the first claw portion and the second claw portion can securely hook onto the periphery of the wound, and reliably prevents the first claw portion and the second claw portion from accidentally coming off the periphery of the wound when the skin tissue around the wound is pulled up.

[0033] In orthopedic treatments such as arthroscopic surgery using an arthroscope, a preparation for treating a lesion in the workspace can be injected into the workspace formed by the retractor of the present invention. That is, the present invention also relates to a preparation for treating a lesion by injecting it into the workspace formed by the retractor of the present invention. The preparation for treating a lesion can be, for example, a preparation for treating damage to articular cartilage or a base for regenerating lost cartilage (such as a sodium alginate sol composition; see Japanese Patent No. 4740369).

[0034] In the first or second invention, an opening maintaining device may be provided for maintaining the opening degree of the first arm and the second arm at a desired position. The opening maintaining device may include a locking member extending in the opening / closing direction of the first operating rod and the second operating rod, a connecting part that swingably connects the locking member to the first operating rod, a locking tooth provided on the second operating rod that releasably locks the locking member, and a finger hook that swings the locking member.

[0035] By providing the opening degree maintaining device having the above configuration, the locking member can be engaged with the locking teeth at a desired opening degree position, including the closed state of the first arm portion and the second arm portion (opening degree 0), to maintain the opening degree, and the locking member can be easily disengaged from the locking teeth by swinging. In particular, by being able to fix the first arm portion and the second arm portion in the closed state (opening degree 0), it becomes easier to insert the device into a wound, for example. [Brief explanation of the drawings]

[0036] [Figure 1] FIG. 2 is an explanatory perspective view showing the retractor of the first embodiment of the present invention in a closed state. [Figure 2]FIG. 2 is an explanatory side view of the retractor of the first embodiment. [Figure 3] FIG. 2 is an explanatory perspective view showing the retractor of the first embodiment in an open state. [Figure 4] FIG. 10 is an explanatory diagram showing a modified example of the opening degree maintaining device. [Figure 5] FIG. 3 is an explanatory view showing the claw portion of the retractor of the first embodiment in a closed state. [Figure 6] FIG. 4 is an explanatory view showing the position of the base end portion of the claw portion in the open state of the retractor of the first embodiment. [Figure 7] FIG. 10 is an explanatory side view showing a closed state of the retractor according to the second embodiment of the present invention. [Figure 8] FIG. 10 is an explanatory view showing the claw portion of the retractor of the second embodiment in a closed state. [Figure 9] FIG. 10 is an explanatory view showing the position of the base end portion of the claw portion in the open state of the retractor of the second embodiment. [Figure 10A] FIG. 10 is a diagram schematically showing the thickness of each claw portion of the wound retractor of the second embodiment. [Figure 10B] FIG. 10 is a diagram schematically showing the thickness of each claw portion of a wound retractor according to a comparative example. [Figure 10C] FIG. 10 is a diagram comparing the areas of the expanded shapes of the claw portions of the retractor of the second embodiment and the claw portions of the retractor of the comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0037] A first embodiment of the present invention will be described with reference to Figures 1 to 6. As shown in Figures 1 and 2, a retractor 1 in the first embodiment includes two first arms 2 and 3 that curve outward, and one second arm 4 that curves outward in the opposite direction to the first arms 2 and 3.

[0038] 1 and 2 show the retractor 1 in a closed state. In the closed state, the second arm 4 is positioned between the first arms 2 and 3. At this time, the first arms 2 and 3 and the second arm 4 overlap with a partial intersection. As shown in FIG. 2, the first arms 2 and 3 and the second arm 4 are bent downward in the same direction from bent portions located midway along their longitudinal directions. The angles of the bent portions of the first arms 2 and 3 and the second arm 4 will be described later.

[0039] 1 and 2, a shaft 5 is provided at an overlapping position on the base end side of the first arms 2, 3 and the second arm 4. The shaft 5 connects the first arms 2, 3 and the second arm 4 so that the tip end side can be rotated open and closed.

[0040] A first operating rod portion 6 extends integrally with both first arms 2 and 3 on the opposite side of the shaft portion 5 from both first arms 2 and 3. A first annular finger hook portion 7 is provided at the end of the first operating rod portion 6.

[0041] A second operating rod 8 extends integrally with the second arm 4 on the opposite side of the shaft 5 from the second arm 4. A second annular finger hook 9 is provided at the end of the second operating rod 8.

[0042] By placing a finger on each of the first finger hook portion 7 and the second finger hook portion 9 and moving the first operating rod portion 6 and the second operating rod portion 8 in a direction toward each other, the first arms 2, 3 and the second arm portion 4 move away from each other via the shaft portion 5, resulting in the open state as shown in Figure 3.

[0043] The first operating rod portion 6, the first finger rest portion 7, the second operating rod portion 8 and the second finger rest portion 9 correspond to the operating portion in the present invention.

[0044] In addition, as an opening maintaining device for maintaining the open / closed state of the first arm portions 2, 3 and the second arm portion 4, a first locking tooth portion 10 is provided on the first operating rod portion 6, and a second locking tooth portion 11 is provided on the second operating rod portion 8.

[0045] The first locking teeth 10 and the second locking teeth 11 are releasably engaged with each other, maintaining the first arm portions 2, 3 and the second arm portion 4 in an open state, as shown in Figure 3. The engagement between the first locking teeth 10 and the second locking teeth 11 can be easily released by applying a force to the first operating rod portion 6 and the second operating rod portion 8 in a direction opposite to the overlapping direction, thereby causing distortion in the first operating rod portion 6 and the second operating rod portion 8.

[0046] The opening maintaining device for maintaining the open state of the first arms 2, 3 and the second arm 4 is not limited to a configuration in which the first locking teeth 10 of the first operating rod 6 mesh with the second locking teeth 11 of the second operating rod 8. An example of another opening maintaining device is shown in Fig. 4. The opening maintaining device shown in Fig. 4 is designed to be able to fix the first arms 2, 3 and the second arm 4 even when they are closed.

[0047] That is, as shown in Fig. 4, the other opening degree maintaining device includes a locking member 101 that passes through the first operating rod portion 6 and the second operating rod portion 8 and extends in the opening / closing direction. A connecting portion 102 is provided at the base end of the locking member 101, and the connecting portion 102 is fixed to the first operating rod portion 6 with a rivet 103. A locking tooth 111 with which the locking member 101 engages is formed in a through-hole 112 of the second operating rod portion 8, through which the locking member 101 passes. A finger hook 104 is formed at the tip of the locking member 101.

[0048] The locking member 101 is biased in the direction toward the locking tooth 111 by the elasticity of the connecting portion 102. When the first operating rod portion 6 and the second operating rod portion 8 are operated in the direction to close (the direction to increase the degree of opening between the first arms 2, 3 and the second arm 4), the locking member 101 resiliently moves past the locking tooth 111, and the degree of opening between the first arms 2, 3 and the second arm 4 is maintained. On the other hand, when the first operating rod portion 6 and the second operating rod portion 8 are operated in the direction to open (the direction to decrease the degree of opening between the first arms 2, 3 and the second arm 4), the locking member 101 can be released from the locking tooth 111 by placing a finger on the finger hook 104 and swinging the locking member 101.

[0049] 1 to 3, first claw portions 12 and 13 are formed at the tip portions of the two first arm portions 2 and 3. The two first claw portions 12 and 13 are provided so that their tips protrude in the opening direction.

[0050] A second claw portion 14 is formed at the tip of the second arm portion 4. The tip of the second claw portion 14 is provided so as to protrude in the opening direction. In other words, the second claw portion 14 protrudes in the opposite direction to the first claw portions 12, 13.

[0051] In the closed state, as shown in FIG. 5, the second claw portion 14 is positioned between the first claw portions 12 and 13, and they overlap each other to form a small bundle.

[0052] Furthermore, as shown in FIG. 5 , the first claw portions 12, 13 located outside the second claw portion 14 are smaller than the second claw portion 14. Specifically, when the overlapping direction of the first claw portions 12, 13 and the second claw portion 14 in the closed state is taken as the thickness dimension, the dimension T1 of each of the first claw portions 12, 13 in the thickness direction is smaller than the dimension T2 of the second claw portion 14 in the thickness direction. This allows the tip portion of the retractor 1 (the first claw portions 12, 13 and the second claw portion 14) to be smoothly inserted into a wound in the skin tissue that has been incised relatively small. Also, as described above, by making the dimension T1 of each of the first claw portions 12, 13 in the thickness direction smaller than the dimension T2 of the second claw portion 14 in the thickness direction, the wound can be opened widely when the retractor is in the open state.

[0053] When the tip is inserted into the wound and the first arms 2, 3 and the second arm 4 are opened, the first claws 12, 13 and the second claw 14 are hooked onto the wound edge. When the open state is reached, the base ends of the first claws 12, 13 and the second claw 14 (the boundary between the first arms 2, 3 and the first claws 12, 13, and the boundary between the second arm 4 and the second claw 14) come into contact with the wound edge and attract each other, opening the wound.

[0054] At this time, as shown in the cross-sectional view of the first arms 2 and 3 (the base ends of the first claws 12 and 13) and the second arm 4 (the base end of the second claw 14) in Figure 6, the first arms 2 and 3 at the base ends of the first claws 12 and 13 and the second arm 4 at the base end of the second claw 14 come into contact with the wound edge W, respectively, widening the wound in three directions. This prevents the wound from extending linearly in its closed state, and allows the wound to remain fully widened.

[0055] 5 and 6, the cross-sectional shape of the first arms 2 and 3 (the base ends of the first claws 12 and 13) is formed as an ellipse that is inclined at a predetermined angle. Therefore, as shown in Fig. 6, the corners of the expanded wound edge W that contact the first arms 2 and 3 (the base ends of the first claws 12 and 13) are smooth, thereby reducing the burden on the wound edge W during expansion. Note that the cross-sectional shape of the first arms 2 and 3 (the base ends of the first claws 12 and 13) is not limited to this, and they may be formed as a non-inclined ellipse.

[0056] Furthermore, when the first arms 2, 3 and the second arm 4 are opened (moved away from each other), the distal ends of the first arms 2, 3 and the distal end of the second arm 4 each trace an arc. Therefore, in the open state, the distal ends of the claws 12, 13, 14 face toward the base end (upward in FIG. 3) compared to when they are closed. This more reliably maintains the state in which the claws 12, 13, 14 are hooked onto the wound edge.

[0057] Furthermore, as shown in FIG. 3 , in the open state, the first claw portions 12 and 13 protrude so that at least their tips are positioned outward relative to the first arms 2 and 3. Similarly, the second claw portion 14 protrudes so that at least its tip is positioned outward relative to the second arms 4. This prevents the arms 2, 3, and 4 from getting in the way when the first claw portions 12 and 13 and the second claw portion 14 are hooked onto the wound edge. This allows the first claw portions 12 and 13 and the second claw portion 14 to hook deeply onto the wound edge. Then, by pulling up the wound retractor 1, which has opened the wound with the first claw portions 12 and 13 and the second claw portion 14 hooked onto the wound edge, the skin tissue around the wound can follow, ensuring a sufficiently large workspace inside the skin tissue.

[0058] When pulling up the retractor 1 that has opened the wound, it is desirable that the first finger hook 7 and the second finger hook 9 are not positioned directly above the wound so that the wound can be observed from above. On the other hand, in order to reduce the load on the fingers imposed by the first finger hook 7 and the second finger hook 9 when pulling up the retractor 1, it is desirable that the pulling direction substantially coincides with the direction of the first arms 2, 3 and the second arm 4. In order to achieve both visibility of the wound and ease of pulling up, which are mutually contradictory conditions, it is desirable that the angle of the bent portions R of the arms 2, 3, and 4 shown in Fig. 2 (the depression angle of the extension line of the insertion area of the arms 2, 3, and 4 into the wound relative to the extension line of the operating rods 6 and 8 in a side view) be set to 140° to 175°.

[0059] Although not shown, the operating rods 6 and 8 may be made relatively long to further improve the visibility of the wound within the angle range of the bent portion R. Alternatively, although not shown, the bent portion R may be formed in a crank shape in side view, and the extending direction of the arms 2, 3, and 4 may be offset from the extending direction of the operating rods 6 and 8.

[0060] As shown in FIG. 3, the length of each of the claw portions 12, 13, 14 is preferably 4 mm to 7 mm, and the angle of the first claw portions 12, 13 relative to the first arm portions 2, 3 and the angle of the second claw portion 14 relative to the second arm portion 4 are preferably set to 2° to 15°.

[0061] The length of each claw portion is relative to the thickness of the skin tissue and the size of the small incision. The thickness of the skin is generally 5 mm to 13 mm (epidermis + dermis: 1 to 4 mm, subcutaneous tissue: 4 to 9 mm). The size of the small incision is 5 mm to 10 mm. When the retractor 1 is in the open state shown in FIG. 3, the width of the wound is 5 mm to 10 mm because tension is applied to the wound edge W. In order for the claw portions 12, 13, and 14 to hook onto the wound edge of this size and elevate tissue with a thickness of 5 mm to 13 mm, the length of the claw portions 12, 13, and 14 is preferably 4 mm to 7 mm, and the angle of the first claw portions 12 and 13 relative to the first arm portions 2 and 3 and the angle of the second claw portion 14 relative to the second arm portion 4 are preferably set to 2° to 15°.

[0062] 3, the first arms 2, 3 and second arms 4 are formed to an appropriate length, and the length from the bent portion R of the first arms 2, 3 and second arms 4 to their tips is preferably 15 mm to 40 mm, and more preferably 30 mm to 40 mm. As mentioned above, the thickness of the skin is generally 5 mm to 13 mm (epidermis + dermis: 1 to 4 mm, subcutaneous tissue: 4 mm to 9 mm). By setting the length of the first arms 2, 3 and second arms 4 to 15 mm to 40 mm, the first arms 2, 3 and second arms 4 can be inserted sufficiently deep into the wound, improving operability when engaging the claws 12, 13, 14 under the skin.

[0063] Next, a second embodiment of the present invention will be described with reference to Figures 7 to 9. Note that the same components as those in the first embodiment will be assigned the same reference numerals as in Figures 1 to 6, and the description thereof will be omitted.

[0064] As shown in a side view in FIG. 7, the retractor 20 of the second embodiment includes two first arms 21 and 22 and two second arms 23 and 24. As shown in FIG.

[0065] As shown in Fig. 8, first claw portions 25, 26 are formed at the tip end of each of the two first arms 21, 22. The two first claw portions 25, 26 are provided so that their tips protrude in the opening direction. Second claw portions 27, 28 are formed at the tip end of each of the two second arms 23, 24. The two second claw portions 27, 28 are provided so that their tips protrude in the opening direction.

[0066] In the closed state, the first claw portions 25, 26 and the second claw portions 27, 28 are alternately positioned and overlap each other, forming a compact bundle.

[0067] 8, the first claw portion 25 and the second claw portion 28 located on the outermost side are smaller than the other first claw portions 26 and the second claw portions 27. In other words, when the thickness dimension is defined as the overlapping direction of the first claw portions 25, 26 and the second claw portions 27, 28 in the closed state, the dimension T3 in the thickness direction of each of the first claw portion 25 and the second claw portion 28 located on the outermost side is smaller than the dimension T4 in the thickness direction of each of the other (inner) first claw portions 26 and the second claw portions 27.

[0068] When the distal end is inserted into the wound and the first arms 21, 22 and the second arms 23, 24 are opened, the first claws 25, 26 and the second claws 27, 28 engage with the wound edge. In the open position, as shown in Fig. 9, the first arms 21, 22 at the base ends of the first claws 25, 26 and the second arms 23, 24 at the base ends of the second claws 27, 28 contact the wound edge W, respectively, widening the wound in four directions. This prevents the wound from extending linearly when closed, and allows the wound to remain fully widened.

[0069] Then, by pulling up the retractor 20 with the first claw portions 25, 26 and the second claw portions 27, 28 hooked deeply onto the edge of the wound, the skin tissue around the wound can be made to follow suit, and a sufficiently large workspace can be secured inside the skin tissue.

[0070] 8 and 9, the cross-sectional shapes of the first arm 21 (proximal end of the first claw portion 25) and the second arm 24 (proximal end of the second claw portion 28), which are located on the outside, are formed as ellipses inclined at a predetermined angle. Therefore, as shown in FIG. 9, the corners of the expanded wound edge W that contact the first arm 21 (proximal end of the first claw portion 25) and the second arm 24 (proximal end of the second claw portion 28) are smooth, thereby reducing the burden on the wound edge W during expansion. Note that the cross-sectional shapes of the first arm 21 (proximal end of the first claw portion 25) and the second arm 24 (proximal end of the second claw portion 28) are not limited to this, and they may be formed as non-inclined ellipses.

[0071] As described above, the thickness dimension T3 of each of the first and second claw portions 25 and 28 located on the outside is smaller than the thickness dimension T4 of each of the first and second claw portions 26 and 27 located on the inside (see FIG. 8). This allows the wound to be opened more widely when the first and second arms are opened, compared to when all of the first and second claw portions have the same thickness dimension.

[0072] This will be explained in detail with reference to Figures 10A to 10C, which show the size relationship between the claw portions. Figure 10A shows a schematic diagram of the retractor 20 of the second embodiment, in which the thickness of the outer claw portions 25, 28 is smaller than that of the inner claw portions 26, 27. Figure 10B shows a schematic diagram of the retractor 20 of the second embodiment, in which all the claw portions have the same thickness (Comparative Example 30). The distance L between both ends in the thickness direction is the same for both the claw portions.

[0073] Then, when each claw portion is expanded and the areas of these expanded shapes are compared, as shown in Figure 10C, where both expanded shapes S1 and S2 are superimposed, the area of the expanded shape S1 by the retractor 20 of the second embodiment is larger than the area of the expanded shape S2 by the comparative example 30.

[0074] As described above, the retractor 20 of the second embodiment can open the wound relatively widely, thereby achieving high workability.

[0075] Furthermore, in the retractor 20 of the second embodiment, in order to reliably obtain the above-mentioned effects, it is preferable that the length of each of the claw portions 25, 26, 27, 28 is 4 mm to 7 mm, and it is preferable that the angle of the first claw portions 25, 26 relative to the first arm portions 21, 22 and the angle of the second claw portions 27, 28 relative to the second arm portions 23, 24 are set to 2° to 15°.

[0076] In the second embodiment, a retractor 20 having two first arms 21, 22 and two second arms 23, 24 is described, but the number of first arms and second arms is not limited to this, and it is possible to provide two or more of each.

[0077] In the above embodiment, as shown in FIGS. 2 and 7, the first arms 2, 3, 21, and 22 and the second arms 4,23,24 However, the retractor of the present invention is not limited to this, and for example, although not shown, the first arm and the second arm may extend linearly toward the tip.

[0078] As described above, the retractor of the present invention can be used to ensure a sufficiently large workspace inside the skin tissue, and a preparation for treating the lesion can be injected into the ensured workspace. The preparation for treating the lesion can be, for example, a preparation for treating damage to articular cartilage or a base for regenerating lost cartilage (such as a sodium alginate sol composition; see Japanese Patent No. 4740369). [Industrial Applicability]

[0079] The retractor of the present invention has a configuration that allows for easy formation of a workspace for arthroscopic surgery while the wound is spread open, and therefore can be suitably used as a medical instrument. [Explanation of symbols]

[0080] 1,20... retractor, 2,3,21,22... first arm portion, 4,23,24... second arm portion, 12,13,25,26... first claw portion, 14,27,28... second claw portion, 6... first operating rod portion (operating portion), 7... first finger hook portion (operating portion), 8... second operating rod portion (operating portion), 9... second finger hook portion (operating portion), 101... locking member, 102... connecting portion, 104... finger hook portion, 111... locking tooth.

Claims

1. A retractor that contacts the edge of an incised skin tissue wound to open the wound, a pair of first arms integrally connected to each other on the base end side and extending toward the tip end; a single second arm portion located between the first arms, the base end of which is rotatably connected to the first arms via a shaft portion and extends toward the tip; an operating unit configured to open and close the first arm unit and the second arm unit, with a state in which the first arm unit and the second arm unit overlap each other being a closed state and a state in which the tip sides of the first arm unit and the second arm unit are separated from each other being an open state; The first arm portion has a first claw portion at a tip portion thereof, the first claw portion protruding in the opening direction to hook onto the edge of the wound, The second arm portion has a second claw portion at a tip portion thereof protruding in the opposite direction to the first claw portion so as to hook onto the edge of the wound, A retractor, characterized in that when the first arm portion and the second arm portion are in a closed state, the first claw portion and the second claw portion overlap each other.

2. The wound retractor according to claim 1, characterized in that, when the overlapping direction of the first claw portion and the second claw portion in the closed state is defined as the thickness direction of each of the first claw portion and the second claw portion, the first claw portion has a thickness dimension smaller than that of the second claw portion.

3. A retractor that contacts the edge of an incised skin tissue wound to open the wound, a plurality of first arms integrally connected to each other on the base end side and extending toward the tip end; a plurality of second arms that are integrally connected to each other at their base ends and alternately arranged with the first arms, and that are rotatably connected to the first arms at their base ends via shafts and extend toward their tip ends; an operating unit configured to open and close the first arm unit and the second arm unit, with a state in which the first arm unit and the second arm unit overlap each other being a closed state and a state in which the tip sides of the first arm unit and the second arm unit are separated from each other being an open state; The first arm portion has a first claw portion at a tip portion thereof, the first claw portion protruding in the opening direction to hook onto the edge of the wound, The second arm portions each have a second claw portion at a tip end thereof, the second claw portion protruding in the opposite direction to the first claw portion so as to hook onto the edge of the wound, A retractor, characterized in that when the first arm portion and the second arm portion are in a closed state, the first claw portion and the second claw portion overlap each other.

4. The wound retractor according to claim 3, characterized in that, when the overlapping direction of the first claw portion and the second claw portion in the closed state is defined as the thickness direction of each of the first claw portion and the second claw portion, at least a pair of claw portions located on the outermost sides of the first claw portion and the second claw portion have a thickness dimension smaller than that of the other claw portions.

5. The retractor according to any one of claims 1 to 4, characterized in that the tip of the first claw portion and the tip of the second claw portion each face toward the base end when the first arm portion and the second arm portion are in an open state compared to when they are in a closed state.

6. the operating section includes a first operating rod section that is provided integrally with the first arm section and extends, and a second operating rod section that is provided integrally with the second arm section, an opening maintaining device for maintaining the opening degree of the first arm portion and the second arm portion at a desired position; The retractor according to any one of claims 1 to 5, characterized in that the opening maintaining device comprises a locking member extending along the opening / closing direction of the first operating rod portion and the second operating rod portion, a connecting portion that connects the locking member to the first operating rod portion in a swingable manner, a locking tooth that is provided on the second operating rod portion and that releasably locks with the locking member, and a finger hook that swings the locking member.

7. 7. The retractor according to claim 1, wherein the first arm and the second arm extend linearly toward their distal ends in a side view.

8. The retractor according to any one of claims 1 to 6, characterized in that when the first arm portion and the second arm portion are in a closed state, the first arm portion and the second arm portion are bent in the same direction in a side view from a bent portion located midway along their longitudinal direction and extend linearly from the bent portion toward their tip.

9. When the first arm and the second arm are in a closed state, the first arm and the second arm have a bent portion formed in a crank shape in a side view at a midpoint in their longitudinal direction, The retractor according to claim 6, characterized in that the extension direction of the first arm portion and the second arm portion is offset from the extension direction of the first operating rod portion and the second operating rod portion in a side view, and the first arm portion and the second arm portion extend in a straight line from the bent portion to the tip.

10. A retractor for forming a workspace in orthopedic surgery, comprising: a pair of first arms integrally connected to each other on the base end side and extending toward the tip end; a single second arm portion located between the first arms, the base end of which is rotatably connected to the first arms via a shaft portion and extends toward the tip; an operating unit configured to open and close the first arm unit and the second arm unit, with a state in which the first arm unit and the second arm unit overlap each other being a closed state and a state in which the tip sides of the first arm unit and the second arm unit are separated from each other being an open state; The first arms each have a first claw portion at a tip end thereof that protrudes in the opening direction, The second arm portion has a second claw portion at a tip end portion thereof protruding in an opposite direction to the first claw portion, A retractor, characterized in that when the first arm portion and the second arm portion are in a closed state, the first claw portion and the second claw portion overlap each other.

11. A retractor for forming a workspace in orthopedic surgery, comprising: a plurality of first arms integrally connected to each other on the base end side and extending toward the tip end; a plurality of second arms that are integrally connected to each other at their base ends and alternately arranged with the first arms, and that are rotatably connected to the first arms at their base ends via shafts and extend toward their tip ends; an operating unit configured to open and close the first arm unit and the second arm unit, with a state in which the first arm unit and the second arm unit overlap each other being a closed state and a state in which the tip sides of the first arm unit and the second arm unit are separated from each other being an open state; The first arms each have a first claw portion at a tip end thereof that protrudes in the opening direction, The second arm portions each include a second claw portion at a tip end thereof, the second claw portion protruding in an opposite direction to the first claw portion, A retractor, characterized in that when the first arm portion and the second arm portion are in a closed state, the first claw portion and the second claw portion overlap each other.

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