JP7683850B2 - surgical instruments - Google Patents

Description

The present invention relates to a surgical instrument, and more particularly to a surgical instrument used in surgery for placing an implant between vertebral bodies that constitute the spine and fixing the distance of the interbody space, and in performing procedures within a joint.

The human spine is made up of multiple bones called vertebrae. In the spine, the intervertebral bodies of the vertebrae aligned from the head to the buttocks are connected via intervertebral discs and joints, and the vertebral arches of the vertebrae aligned above and below are connected by intervertebral joints and ligaments to form the spine (see Figure 11).

In such a spine, there are diseases such as spondylosis, spondylolisthesis, spinal instability, spinal canal stenosis, intervertebral disc degeneration, intervertebral disc herniation, and degenerative herniation of intervertebral disc. In diseases caused by aging or in athletes, the degeneration of the intervertebral disc narrows the space between the vertebral bodies. When the space between the vertebral bodies narrows, for example, osteoarthritis of the posterior joints may occur, causing chronic pain or herniation. In order to return such a narrowed space between the vertebral bodies to a normal state, that is, the state before the space between the vertebral bodies narrowed, implants are placed between the vertebral bodies.

Conventionally, when placing an implant between the vertebral bodies of vertebrae, an open surgical procedure was performed in which the patient's back was incised to expose the spine and the implant was placed in. However, in order to reduce the burden on the patient, surgery for placing an implant between the vertebral bodies of vertebrae has been performed in recent years using less invasive surgery, and instruments used in this surgery have also been developed (see Patent Document 1).

Patent Document 1 discloses an expanding introducer for spinal surgery. This expanding introducer for spinal surgery is designed to expand the space between the vertebral bodies by inserting the tip of the expanding tube between the vertebral bodies of the spine. Then, by inserting an instrument or an implant through the space inside the expanding tube, it is possible to perform operations between the vertebral bodies and to place an implant between the vertebral bodies.

However, since the expander tube of Patent Document 1 has a circular cross section, the size of the instruments and implants that can pass through the space inside the expander tube is limited. Moreover, when using instruments and implants with a cross section other than a circular one, only those with a cross section significantly smaller than the cross section of the expander tube can be used. For example, implants with a rectangular cross section are used, but if one wants to ensure a certain thickness (length of the short side) of the implant, only those with a long side significantly smaller than the inner diameter of the expander tube can pass through the expander tube. Therefore, the expander tube of Patent Document 1 significantly limits the surgeries that can be performed and the size of the implants to be placed.

Meanwhile, a tube with a substantially rectangular cross section has also been developed as a dilator tube (sleeve) to be inserted between the vertebral bodies of the vertebrae (Patent Document 2). The tube in Patent Document 2 is for inserting an implant with a substantially rectangular cross section between the vertebral bodies, and the shape of its internal space is formed to be substantially similar to the cross section of the implant to be inserted. Therefore, an implant with a substantially rectangular cross section and a size equivalent to the cross-sectional area of the tube can be stably placed between the vertebral bodies.

However, in the tube of Patent Document 2, when the tube is inserted between the vertebral bodies, the space between the vertebral bodies can be expanded by the length of the short side of the tube, but if the implant placed between the vertebral bodies becomes thick, the thickness of the tube itself must be made thicker. In this case, in a patient with a narrow intervertebral space, the difference between the thickness of the tube and the space between the vertebral bodies becomes large, so it takes a lot of effort to insert the tube and the burden on the patient is also large. In addition, some patients may have difficulty inserting such a thick tube. In other words, the situations in which the tube of Patent Document 2 can be used are limited.

Meanwhile, tubes with an elliptical cross section have also been developed as tubes to be inserted between the vertebral bodies of vertebrae (Non-Patent Document 1). By using a tube of this shape, compared to a tube with a circular cross section, even an implant with a long side (length of the tube in the long axis direction) can be placed between the vertebral bodies through the space inside the tube while maintaining a certain degree of thickness (length of the tube in the short axis direction).

Moreover, Non-Patent Document 1 describes that if a tube is inserted between vertebral bodies with the direction of the vertebral bodies lined up and the short axis direction of the tube parallel, and the tube is rotated from the inserted state (the direction of the vertebral bodies lined up and the long axis direction of the tube are made parallel), the space between the vertebral bodies can be made wider than when the tube is inserted. This makes it possible to make the space between the vertebral bodies wider than the length of the short axis of the tube while reducing the burden of inserting the tube between the vertebral bodies, making it easier to operate between the vertebral bodies and to install the implant.

Special Publication No. 2014-517710 Special table 2018-527986 publication

Masaru Nagahama et al., "Percutaneous Endoscopic Lumbar Interbody Fusion: PETLIF," Spine and Spinal Cord, Vol. 32, No. 9, pp. 843-849, Miwa Shoten, September 25, 2019

However, in the case of the tube of Non-Patent Document 1, when the long axis direction is parallel to the direction in which the vertebrae are aligned (hereinafter referred to as the expanded state), a force is applied to the tube from the vertebrae along the long axis direction. If the direction of the force does not completely match the long axis direction, a force is applied that tries to return the tube to its original state. Therefore, in order to maintain the position of the tube in the expanded state, it is necessary to maintain the rotation of the tube, which requires an instrument and an operator to maintain the rotation, and this may increase the difficulty of the procedure.

In view of the above circumstances, an object of the present invention is to provide a surgical instrument that can reduce the difficulty of surgery between vertebral bodies.

The surgical instrument of the first invention is an instrument used for surgery between vertebrae of the spine, and comprises a first member having a pair of parallel first surfaces extending along a first direction and a pair of parallel second surfaces intersecting the pair of first surfaces extending along the first direction, and a second member having a groove portion for accommodating the first member and communicating between a first end and a second end, the groove portion of the second member having a bottom wall extending along the axial direction of the groove portion and a pair of parallel side walls extending along the axial direction of the groove portion, the second member being characterized in that a distance between inner surfaces of the pair of side walls is formed to a length that allows the first member and the second member to move relatively along the axial direction of the groove portion with the first direction of the first member and the axial direction of the groove portion of the second member parallel to each other.

According to the first invention, the distance between the vertebral bodies can be increased by inserting the first end of the first member in the first direction between the vertebral bodies so that the pair of first surfaces faces the vertebral bodies. Then, the first end of the second member can be positioned between the vertebral bodies by moving the second member along the first member while the first member is housed in the groove. Then, the first member can be removed from the second member to form a route communicating between the vertebral bodies via the groove.

1A is a schematic explanatory diagram of the surgical instrument 1 of this embodiment, in which (A) is a schematic oblique view, (B) is a view from the first end face side of the first end portion 10a of the first member 10, and (C) is a cross-sectional view of a cross section perpendicular to the first direction of the first member 10. 1A is a schematic perspective view of a guide portion 30, FIG. 1B is a schematic perspective view of a second member 20, and FIG. 1C is a schematic perspective view of a first member 10. FIG. 1A and 1B are schematic explanatory diagrams of how to use the surgical instrument 1 of this embodiment, in which (A) is an explanatory diagram of the guide portion 30 inserted between the vertebrae VB, and (B) is an explanatory diagram of the guide portion 30 just before the first member 10 is inserted through the wire portion 31. 1A and 1B are schematic explanatory diagrams of how to use the surgical instrument 1 of this embodiment, in which (A) is an explanatory diagram of the first member 10 inserted into the wire portion 31 of the guide portion 30, (B) is an explanatory diagram of the first member 10 rotated around the wire portion 31 of the guide portion 30, and (C) is an explanatory diagram of the first member 10 accommodated in the groove portion 20h of the second member 20. 1A is a schematic explanatory diagram of a method of using the surgical instrument 1 of this embodiment, in which (A) is a standalone explanatory diagram of the state in which the first member 10 is removed from the groove portion 20h of the second member 20, (B) is a standalone explanatory diagram of the state in which only the guide portion 30 is positioned in the groove portion 20h of the second member 20, and (C) is a standalone explanatory diagram of the state in which the guide portion 30 has been removed from the groove portion 20h of the second member 20. 1A and 1B are schematic explanatory diagrams of how to use the surgical instrument 1 of this embodiment, in which (A) is an explanatory diagram of the state in which the guide portion 30 is inserted between the vertebrae VB, and (B) is an explanatory diagram of the state in which the first member 10 is inserted through the wire portion 31 of the guide portion 30. 1A and 1B are schematic explanatory diagrams of how to use the surgical instrument 1 of this embodiment, in which (A) is an explanatory diagram of the state in which the first end 10a of the first member 10 is inserted between the vertebrae VB, and (B) is an explanatory diagram of the state in which the first member 10 inserted between the vertebrae VB is rotated around the wire portion 31 of the guide portion 30. 1A is a schematic explanatory diagram of a method of using the surgical instrument 1 of this embodiment, in which (A) is an explanatory diagram of a state in which a first end portion 20a of the second member 20 is inserted between vertebrae VB with the first member 10 accommodated in a groove portion 20h of the second member 20, and (B) is an explanatory diagram of a state in which the first member 10 is removed from the groove portion 20h of the second member 20 with the first end portion 20a of the second member 20 inserted between vertebrae VB. 1A is an explanatory diagram of a state in which only the guide portion 30 is arranged in the groove portion 20h of the second member 20, and FIG. 1B is an explanatory diagram of a state in which the guide portion 30 has been removed from the groove portion 20h of the second member 20. 1A and 1B are schematic explanatory diagrams of how to use the surgical instrument 1 of this embodiment, in which (A) and (B) are explanatory diagrams of the state in which a shaver 40 is inserted between the vertebrae VB through the groove portion 20h of the second member 20, and (C) is an explanatory diagram of the state in which an implant IP is inserted between the vertebrae VB through the groove portion 20h of the second member 20. 1A and 1B are schematic diagrams of a vertebra C, in which (A) is a rear view and (B) is a side view. 1A and 1B are schematic enlarged partial explanatory diagrams of a vertebra C, in which (A) is a side view and (B) is a rear obliquely downward view. 1A is a schematic explanatory diagram showing an example of a shaver 40, and FIG. 1B is a schematic explanatory diagram showing an example of a tool 50 for inserting an implant IP between vertebrae VB. (A) and (B) are schematic explanatory diagrams of the state in which a shaver 40 is inserted between the vertebrae VB through the groove portion 20h to perform cutting operation, and (B) is a schematic explanatory diagram of the state in which an implant IP is inserted between the vertebrae VB through the groove portion 20h of the second member 20. FIG. 4 is a schematic cross-sectional view of a second member 20 according to another embodiment. 11 is a schematic explanatory diagram of a second member 20 according to another embodiment. FIG. 13 is a schematic explanatory diagram of a state in which an engagement portion 51 of a handle 50 is engaged with a second end portion 10b of a first member 10 and the first member 10 is pulled out from a second member 20. FIG. 13 is a schematic explanatory diagram of a state in which the second end 10b of the first member 10 is inserted into an engagement hole 50h of the handle 50 and the first member 10 is rotated. FIG. 1A is a schematic explanatory diagram of a hammer 60 alone, in which (A) is a plan view, (B) is a side view, and (B) is a perspective view. 13 is a schematic explanatory diagram of a state in which a guide member 31 is disposed in a guide groove 62g of a hammer head 62 of a hammer 60. FIG. 1 is a schematic explanatory diagram of a state in which a hammer head 62 of a hammer 60 is moved along a guide member 31 and a striking surface 62s of the hammer head 62 is striking an end face of a second end 10b of a first member 10. FIG. 1A is a schematic side view of a supply device 70, and FIG. 1B is a schematic cross-sectional view of the supply device 70, showing a state in which a shaft-shaped member 75a of a pushing member 75 is inserted into an introduction passage 72h of a tubular portion 72. FIG. FIG. 13 is a schematic explanatory diagram showing a state in which bone to be grafted is being supplied between vertebrae VB using a supplying instrument 70. FIG. 11 is a schematic explanatory diagram of a first member 10 according to another embodiment. (A) is a schematic diagram of the first member 10 with a handle 50B attached, (B) is a single oblique view of the first member 10 connected to the handle 50B, and (C) is a single plan view of the first member 10 connected to the handle 50B. 1A is a schematic diagram of a shaver 40 with a handle 50B attached, FIG. 1B is a perspective view of the shaver 40 connected to the handle 50B, and FIG. 1C is a plan view of the shaver 40 connected to the handle 50B. 1A is a perspective view of the handle 50B alone, FIG. 1B is a schematic cross-sectional view of the handle 50B alone, and FIG. 1C is a schematic cross-sectional view of the handle 50B with the first member 10 connected to it.

The surgical instrument of this embodiment relates to a surgical instrument used for surgery to place an implant between vertebral bodies that make up the spine and fix the space between the vertebral bodies, or for enlarging an intervertebral foramen.

The surgical instruments of the present embodiment are not particularly limited to any particular surgery or procedure, and may be used in any surgery or procedure in which a treatment is performed between vertebral bodies. For example, the surgical instruments of the present embodiment may be used to hold the space between vertebral bodies during surgery such as lumbar interbody fusion (PLIF: Posterior Lumbar Interbody Fusion/TLIF: Transforaminal Lumbar Interbody Fusion), lumbar anterior lateral interbody fusion (OLIF: Oblique Lateral Interbody Fusion), lumbar minimally invasive lateral fusion (XLIF: Extreme Lateral Interbody Fusion), and lumbar anterior interbody fusion (ALIF: Anterior Lumbar Interbody Fusion), or to insert surgical instruments or bone to be transplanted between vertebral bodies. The surgical instruments of the present invention may also be used to retrieve tissue from the spine.

In the following example, the surgical instrument of this embodiment is described as being inserted between vertebral bodies through Kambin's triangle (Safety triangle, see Figures 11 and 12), but the position at which the surgical instrument of this embodiment is inserted between vertebral bodies is not limited to Kambin's triangle. For example, the surgical instrument of the present invention may be inserted between vertebral bodies from the side of the vertebra or from behind the vertebra. Note that Kambin's triangle TR in a two-dimensional plane is a triangle with its base at the superior endplate of the lower vertebral body, its height at the intervertebral foramen side of the superior articular process, and its hypotenuse at the upper exiting nerve root (hereinafter sometimes simply referred to as the nerve).

<Surgical instrument 1 of this embodiment>
As shown in Fig. 1 and Fig. 2, the surgical instrument 1 of this embodiment includes a first member 10, a second member 20, and a guide member 30. The first member 10 is an instrument used to widen a gap between the vertebral bodies VB of the vertebrae V of the spine C. The second member 20 is an instrument used to secure a path for an operator to access between the vertebral bodies VB by communicating between the vertebral bodies VB of the vertebrae V of the spine C and the outside. The guide member 30 is an instrument used to guide the movement of the first member 10 when the first member 10 is introduced between the vertebral bodies VB of the vertebrae V of the spine C. Each instrument will be described below with reference to the drawings.

The guide member 30 is not necessarily a necessary tool for the operation between the vertebral bodies VB described below. However, in order to easily and accurately perform the procedure, it is desirable to use the guide member 30 when inserting the first member 10 and the second member 20 between the vertebral bodies VB. In other words, it is desirable to use the guide member 30 in order to accurately and quickly insert the first member 10 between the vertebral bodies VB of the vertebrae V of the spine C.

<First member 10>
As shown in Fig. 1 and Fig. 2(B), the first member 10 is a rod-shaped member extending along the axial direction (the first direction in the claims). The first member 10 has a pair of first surfaces 11, 11 parallel to the axial direction and parallel to each other. The pair of first surfaces 11, 11 are formed as flat planes. The first member 10 also has a pair of second surfaces 12, 12 parallel to the axial direction and parallel to each other. Moreover, the pair of second surfaces 12, 12 are provided so as to be perpendicular to the pair of first surfaces 11, 11. In other words, the first member 10 has a cross section perpendicular to its axial direction formed in a substantially rectangular shape with the pair of first surfaces 11, 11 as the long sides and the pair of second surfaces 12, 12 as the short sides.

The distance W1 between the pair of second surfaces 12, 12 is longer than the distance T1 between the pair of first surfaces 11, 11 (in other words, the distance T1 between the pair of first surfaces 11, 11 is shorter than the distance W1 between the pair of second surfaces 12, 12). The difference between the distance W1 and the distance T1 is not particularly limited as long as it is appropriately adjusted according to the patient and surgery using the surgical instrument 1 of this embodiment. For example, when used in interbody fusion surgery, it is desirable to make the difference between the distance W1 and the distance T1 as small as possible (about 1 to 3 mm). Note that, as described later, when forming a space between the vertebrae VB that is larger than the distance T1 between the pair of first surfaces 11, 11, multiple first members 10 with different sizes of the distance W1 and the distance T1 may be used. In other words, it is preferable to insert the first members 10 between the vertebrae VB starting from the one with the smallest size of the distance W1 and the distance T1, and gradually expand the space between the vertebrae VB.

In addition, the end face of the first end 10a of the first member 10 in the axial direction (the end face located on the left side in Figs. 1 and 2) is formed as a flat face perpendicular to the pair of first faces 11, 11 and/or the pair of second faces 12, 12. Moreover, a pair of inclined faces 11f, 11f is formed on the first end 10a. The pair of inclined faces 11f, 11f are formed so that the distance between them becomes shorter toward the end face of the first end 10a. In other words, the pair of inclined faces 11f, 11f are formed so that they incline toward the other first face 11 toward the end face of the first end 10a.

The first member 10 has a through hole 10h penetrating the end face of the first end 10a and the end face of the second end 10b (the end located on the right side in Figs. 1 and 2). The through hole 10h is formed parallel to the axial direction of the first member 10 (see Fig. 1C). The through hole 10h is connected to a recess 10d formed on the end face of the first end 10a, which accommodates a stopper 32 of the guide member 30 (described later) (see Fig. 1B). The recess 10d is a substantially hemispherical recess with a radius of curvature larger than the radius of the through hole 10h, and is formed to a size capable of accommodating the stopper 32 of the guide member 30.

<Second member 20>
As shown in Fig. 1 and Fig. 2(C), the second member 20 is a gutter-shaped member having a groove portion 20h extending along the axial direction. Specifically, the second member 20 includes a flat bottom wall 21 extending along the axial direction, and a pair of flat side walls 22, 22 extending along the axial direction provided on both sides of the bottom wall 21. One end edge (the lower end edge in Fig. 1(B) and (C)) of the pair of side walls 22, 22 is connected to the side end edge of the bottom wall 21. The pair of side walls 22, 22 are provided so that they are parallel to each other and their inner surfaces are approximately perpendicular to the inner surface of the bottom wall 21. In other words, the second member 20 has a groove portion 20h extending along the axial direction surrounded by the bottom wall 21 and the pair of side walls 22, 22. The outer surfaces of the pair of side walls 22, 22 are also formed as flat surfaces, and the pair of side walls 22, 22 are also formed as parallel surfaces.

The groove portion 20h of the second member 20 is open between the edges (upper edges in Figs. 1B and 1C, hereinafter sometimes referred to as the upper edges) of the pair of side walls 22, 22 located opposite the bottom wall 21. The second member 20 has openings of the groove portion 20h formed at its first end portion 20a (the end portion located on the left side in Figs. 1 and 2) and second end portion 20b (the end portion located on the right side in Figs. 1 and 2). In other words, the groove portion 20h of the second member 20 is a groove with an open top that communicates between the first end portion 20a and the second end portion 20b.

The groove 20h of the second member 20 is formed to a size that can accommodate the above-mentioned first member 10 (see FIG. 1). Moreover, when the first member 10 is accommodated in the groove 20h so that the axial direction of the groove 20h and the axial direction of the first member 10 are parallel, the groove 20h is formed to a size that allows the first member 10 and the second member 20 to move (slide) relatively along the axial direction of the groove 20h. Specifically, the distance W2 between the inner surfaces of the pair of side walls 22, 22 is formed to be the same as the distance W1 between the surfaces of the pair of second surfaces 12, 12 of the first member 10 (a state in which the inner surfaces of the pair of side walls 22, 22 and the pair of second surfaces 12, 12 of the first member 10 are in surface contact) or slightly longer (see FIGS. 1B and 1C). For example, the difference between the distance W1 and the distance W2 is formed to be 1 mm or less. Then, even if the first member 10 and the second member 20 are moved relatively, the axial directions of both can be moved while being maintained substantially parallel.

The height T2 of the pair of side walls 22, 22 of the groove portion 20h of the second member 20 (the length from the inner surface of the bottom wall 21 to the upper edge of the side wall 22) is not particularly limited. It may be the same as the distance T1 between the pair of first surfaces 11, 11 of the first member 10, or it may be shorter or longer than the distance T1. As will be described later, in order to insert the first end 20a of the second member 20 between the vertebral bodies VB with the first end 10a of the first member 10 disposed between the vertebral bodies VB, it is desirable that the distance T2 be equal to or slightly longer than the distance T1.

The second end 20b of the second member 20 is provided with a flange portion 25 that is held when the second member 20 is moved. This flange portion 25 also has a function of restricting the movement of the second member 20. This flange portion 25 is provided so that when an end face of the flange portion 25 is placed at a predetermined position of the second end 10b of the first member 10, the end face of the first end 10a of the first member 10 protrudes a predetermined length from the end face of the first end 20a of the second member 20 (see FIG. 1(A)). Note that if the second member 20 can be operated or positioned without the flange portion 25, the flange portion 25 does not necessarily have to be provided.

<Guide Member 30>
As shown in FIG. 1 and FIG. 2A, the guide member 30 has a wire portion 31 and a stopper 32 provided at the tip of the wire portion 31.

The wire portion 31 is made of a material having a certain degree of flexibility and high tensile strength. For example, a known guide wire used in posterior spinal surgery using a percutaneous pedicle screw (PPS) or in the treatment of a fracture can be used as the wire portion 31. The wire portion 31 is inserted through the through hole 10h of the first member 10 described above, and has a diameter smaller than the diameter of the through hole 10h of the first member 10.

The stopper 32 is provided at the tip (first end) of the wire portion 31. The stopper 32 is, for example, a sphere made of the same material as the wire portion 31. The stopper 32 is a sphere, and is formed with a diameter larger than the diameter of the wire portion 31 and the diameter of the through hole 10h. The stopper 32 is provided to prevent the first member 10 from falling off the tip of the wire portion 31 when the rear end of the wire portion 31 is inserted into the through hole 10h of the first member 10 from the first end 10a. In other words, the stopper 32 is provided so that the first end 10a of the first member 10 does not move beyond the stopper 32 even if the first member 10 is moved along the wire portion 31.

It is preferable that the sphere forming the stopper 32 is formed so that its radius is approximately the same as the radius of curvature of the recess 10 d of the first member 10 .
Furthermore, although the stopper 32 is not limited to a sphere, if it is a sphere, it is possible to prevent blood vessels, nerves, etc. from being damaged by the tip of the wire portion 31 when inserting the wire portion 31 of the guide member 30 into the triangle TR of the cam bin.

<Example of surgery using the surgical instrument 1 of this embodiment>
Hereinafter, with reference to the drawings, a case where an operation is performed to place an implant IP between vertebral bodies VB using the surgical instrument 1 of this embodiment will be described. The following explanation is based on the premise that the procedure is performed while checking the position of the surgical instrument 1 of this embodiment in the patient's body under X-ray fluoroscopy.

In addition, in addition to the above-mentioned first member 10, second member 20, and guide member 30, a shaver 40 (see FIG. 13A), an implant insertion instrument 45 (see FIG. 13B), and other instruments for performing procedures between vertebral bodies VB are also described. These shavers 40, implant insertion instruments 45, and other instruments may be commercially available known instruments. These shavers 40, implant insertion instruments 45, and other instruments may also be included in the surgical instrument 1 of this embodiment.

In the drawings, in order to make it easier to understand the relationship between the surgical instrument 1 of this embodiment and the vertebral body VB during surgery, the patient's muscles and other tissues present around the spine C are omitted. In addition, while Figures 6 to 10 depict the surgical instrument 1 of this embodiment and the vertebra VB in order to show the interference state between the surgical instrument 1 of this embodiment and the vertebra VB, Figures 3 to 5 and 14 depict only the surgical instrument 1 of this embodiment in order to make it easier to understand the relationship between the instruments.

The following surgery is described on the assumption that the relative positions of each instrument and the vertebra VB are confirmed using X-ray fluoroscopic images. If X-ray fluoroscopic images are not used, the relative positions of each instrument and the vertebra VB are confirmed using an endoscope or the like.

First, a hole (hereinafter, simply referred to as an introduction hole) for inserting the surgical instrument 1 of this embodiment is formed in the back of the patient on whom the procedure is to be performed. The position at which the introduction hole is formed varies depending on the patient, but the introduction hole is formed at a position where the tip of the guide member 30, the first end 10a of the first member 10, and the first end 20a of the second member 20 can be inserted between the vertebral bodies VB through the triangle TR of the cam bin (see Figs. 10 and 11) when the surgical instrument 1 of this embodiment is inserted through the introduction hole.

Once an introduction hole has been formed in the patient's back, the guide member 30 is first inserted through the introduction hole, through the triangle TR of the cam pin, into the intervertebral disc between the vertebrae VB (see Figs. 3(A) and 6(A)). Note that the base end of the wire portion 31 of the guide member 30 is positioned outside the patient's body through the introduction hole.

When the wire portion 31 of the guide member 30 is positioned, the first member 10 is inserted from the rear end of the wire portion 31. Specifically, the wire portion 31 is inserted from the end face of the first end portion 10a of the first member 10 into the through hole 10h (see FIG. 3B). Then, the first member 10 is moved along the wire portion 31 (see FIG. 6B). Then, the first end portion 10a of the first member 10 is inserted into the intervertebral disc between the adjacent vertebral bodies VB (see FIGS. 4A and 7A). At this time, the first member 10 maintains its position such that the pair of first faces 11, 11 intersect with the direction in which the vertebral bodies V are arranged. That is, the first end portion 10a of the first member 10 is inserted into the intervertebral disc between the adjacent vertebral bodies VB in a position such that the pair of first faces 11, 11 are in contact with the opposing faces of the vertebral bodies VB (see FIG. 7A). Then, if the gap between the adjacent vertebral bodies VB is narrower than the distance between the pair of first surfaces 11, 11 of the first member 10, the gap between the adjacent vertebral bodies VB is widened to the distance T1 between the pair of first surfaces 11, 11. At this time, if a pair of inclined surfaces 11f, 11f is provided on the first end portion 10a of the first member 10, the first end portion 10a of the first member 10 can be inserted between the vertebral bodies VB with a relatively small force. Note that even when the first end portion 10a of the first member 10 is inserted between the vertebral bodies VB, the second end portion 10b of the first member 10 remains exposed to the outside of the patient's body.

When the first end 10a of the first member 10 is inserted into the intervertebral disc between the adjacent vertebral bodies VB, the first member 10 is rotated around the wire portion 31 in order to widen the gap between the adjacent vertebral bodies VB (see Figs. 4(A) and 7(A)). Specifically, a handle 50 is attached to the second end 10b of the first member 10 (see Figs. 4(A) and 4(B)), and the first member 10 is rotated by the handle 50 until the pair of second surfaces 12, 12 of the first member 10 are in a position where they contact the opposing surfaces of the vertebral body VB (until the first member 10 is rotated 90 degrees) (see Figs. 4(B) and 7(B)). Then, since the distance W1 between the pair of second surfaces 12, 12 of the first member 10 is longer than the distance T1 between the pair of first surfaces 11, 11 of the first member 10, the gap between the adjacent vertebral bodies VB is widened more than when the first end 10a of the first member 10 is inserted. In other words, the gap between the adjacent vertebral bodies VB is widened to the distance W1 between the pair of second surfaces 12, 12. Moreover, since the pair of second surfaces 12, 12 are flat surfaces parallel to each other, the first member 10 is stably disposed between the adjacent vertebral bodies VB even in the rotated state. In other words, even if a force is applied that narrows the gap between the adjacent vertebral bodies VB, the first member 10 does not return to its original state (i.e., the state inserted into the intervertebral disc) and is likely to be maintained in the rotated state.

The handle 50 may be fixed to the second end 10b of the first member 10. However, if the handle 50 is made detachable from the second end 10b of the first member 10, the ease of handling of the first member 10 can be improved.

When the first member 10 is rotated, the second member 20 is moved along the first member 10. Specifically, the second member 20 is moved along the first member 10 so that the second end 10b of the first member 10 is inserted from the first end 20a of the second member 20 into the groove 20h. Then, with the first member 10 housed in the groove 20h of the second member 20, the first end 20a of the second member 20 is inserted into the gap between the adjacent vertebral bodies VB (see Fig. 4(C) and Fig. 8(A)). Then, when the second member 20 is inserted until the end face of the flange portion 25 is at a predetermined position of the second end 10b of the first member 10, the edge of the first end 20a of the second member 20 is positioned at a position retreated by a predetermined position from the end face of the first end 10a of the first member 10. Even in this state, the insertion amount of the first end 10a of the first member 10 between the adjacent vertebral bodies VB is adjusted so that the edge of the first end 20a of the second member 20 is inserted into the gap between the adjacent vertebral bodies VB.

When the second member 20 is moved along the first member 10, the second member 20 is disposed so that its pair of side walls 22, 22 face the pair of second surfaces 12, 12 of the first member 10, respectively. Moreover, the bottom wall 21 of the second member 20 is in contact with the first surface 11 (lower in FIG. 8 ) located on the nerve side (exiting nerve root side) of the pair of first surfaces 11, 11 of the first member 10. Then, the nerve can be protected from the instruments operated at the position of the Cambin triangle TR by the bottom wall 21 and the side wall 22 of the second member 20. Moreover, the pair of side walls 22, 22 of the second member 20 are in a state where their outer surfaces are in contact with the opposing surfaces of the vertebral bodies VB, so that the second member 20 can easily maintain the gap between the vertebral bodies VB even if a force is applied that narrows the gap between the adjacent vertebral bodies VB. Even when the first end 10a of the second member 20 is inserted between the vertebral bodies VB, the second end 20b is exposed to the outside of the patient's body.

When the first end 20a of the second member 20 is inserted into the gap between the adjacent vertebral bodies VB, the first member 10 and the guide member 30 are removed (see Figs. 5(B), 8(B), and 9(A)), and only the second member 20 is left between the vertebral bodies VB (see Figs. 5(C) and 9(B)). Then, the second end 20b of the second member 20 is exposed to the outside of the patient's body, and the groove 20h of the second member 20 forms a route (space) that communicates from the outside of the patient's body to the space between the vertebral bodies VB (see Figs. 8(C) and 9(B)).

In this way, if a route (space) that communicates from outside the patient's body to between the vertebral bodies VB is formed by the groove portion 20h of the second member 20, the shaver 40 or other instruments (e.g., ring curettes, etc.) can be inserted between the vertebral bodies VB through this route (groove portion 20h) to resect the intervertebral disc between the vertebral bodies VB or the vertebral body VB itself. Note that the shaver 40 may also be provided with a through hole that penetrates the axial direction through which the guide member 30 can be inserted, and the shaver 40 may be inserted or the resection operation may be performed with the guide member 30 inserted. This limits the movement range of the shaver 40, making it easier to prevent the shaver 40 from coming into contact with surrounding tissues when the shaver 40 is inserted or the resection operation is performed with the shaver 40.

Through this route (groove 20h), an implant IP can be placed at a predetermined position between the vertebral bodies VB by an implant insertion instrument 45 (see FIG. 9B). Moreover, since the groove 20h of the second member 20 has an opening on the side opposite to the bottom wall 21, even an instrument or an implant IP larger than the cross-sectional area of the groove 20h can be inserted between the vertebral bodies VB through the route (groove 20h) as long as its width is shorter than the distance W2 between the inner surfaces of the pair of side walls 22, 22. For example, an implant IP with a height suitable for the space between the vertebral bodies VB is used, but the width of the implant IP may be shorter than the distance W2 between the inner surfaces of the pair of side walls 22, 22, but its height may be greater than the height T2 of the pair of side walls 22, 22 (in other words, the depth of the groove 20h). However, since the second member 20 has an opening on the side opposite to the bottom wall 21, even such an implant IP can be inserted between the vertebral bodies VB. In particular, if an implant IP with a variable height is used, it can be adjusted to an appropriate height after being inserted between the vertebral bodies VB. In this case, if the implant IP is set to the smallest (lowest height), even an implant IP that is several times as high as the height T2 of the pair of side walls 22, 22 when inserted between the vertebral bodies VB can be inserted between the vertebral bodies VB. Then, the hole (hole) formed in the patient can be made smaller than the height of the implant IP when it is actually placed between the vertebral bodies VB, so that the burden on the patient during the treatment can be reduced. In addition, when recovering removed tissue, etc., even if the removed tissue, etc. is larger than the cross-sectional area of the groove portion 20h, it can be recovered through the route (groove portion 20h) as long as it is up to a certain size. Then, since it is not necessary to make the tissue to be recovered small, the burden on the practitioner can be reduced and the treatment time can be shortened.

As described above, by using the surgical instrument 1 of this embodiment, the space between the vertebral bodies VB can be easily and reliably widened by the first member 10, and a route that communicates between the outside of the body and the space between the vertebral bodies VB can be formed by the groove 20h of the second member 20. Moreover, even an instrument or the like that is larger than the cross-sectional area of the groove 20h of the second member 20 can be inserted between the vertebral bodies VB, and even tissue or the like that is larger than the cross-sectional area of the groove 20h of the second member 20 can be retrieved from between the vertebral bodies VB.

In addition, if the gap between the adjacent vertebral bodies VB cannot be widened to a predetermined distance at once, a plurality of first members 10 and second members 20 of different sizes may be used to widen the gap to the desired distance. In this case, the small first member 10 and the small second member 20 are used to widen the gap between the vertebral bodies VB by the above-mentioned method, and the small second member 20 is placed between the vertebral bodies VB. Then, the large first member 10 is placed between the vertebral bodies VB through the groove 20h of the small second member 20. Specifically, a large first member 10 having a distance T1 between a pair of first faces 11, 11 longer than the distance T1 between the pair of first faces 11, 11 of the small first member 10 but equal to or shorter than the distance W2 between the inner faces of a pair of side walls 22, 22 of the small second member 20 is placed between the vertebral bodies VB through the groove 20h of the small second member 20. Then, after the small second member 20 is removed, the large first member 10 is rotated to further widen the gap between the vertebral bodies VB, and then the large second member 20 is inserted. Finally, by removing the large first member 10, the gap between the adjacent vertebral bodies VB is widened to a predetermined distance, and a route communicating from outside the body to the vertebral bodies VB can be formed by the large second member 20. The sizes of the small first member 10 and the large first member 10 are not particularly limited, but if the distance T1 between the pair of first faces 11, 11 of the small first member 10 and the distance W1 between the pair of second faces 12, 12 of the large first member 10 are the same length, surgery or procedures can be easily performed.

In order to easily widen the gap between the adjacent vertebral bodies VB, it is desirable to first use the first member 10 having a square cross section before using the first member 10 having a rectangular cross section as described above. Between the vertebral bodies VB of a patient who is to undergo treatment using the surgical instrument 1 of this embodiment, a circular hole for inserting the first member 10 is formed before performing a treatment to widen the gap between the vertebral bodies VB. Therefore, if the first member 10 having a square cross section is first inserted between the adjacent vertebral bodies VB, it becomes easier to then rotate the first member 10 having a rectangular cross section to widen the gap between the adjacent vertebral bodies VB. The first member 10 having a square cross section used here may have a cross-sectional shape and size that allows it to be inserted into the circular hole described above. For example, the first member 10 may be formed such that the distance T1 between the pair of first surfaces 11, 11 and the distance W1 between the pair of second surfaces 12, 12 are the same, and the lengths of the distance T1 and the distance W1 are approximately the same as the diameter of the circular hole.

When using such a first member 10 having a square cross section, the procedure is carried out as follows.
First, the first end 10a of the first member 10 having a square cross section is inserted between the adjacent vertebral bodies VB.
At this time, the first member 10 having a square cross section is inserted between the adjacent vertebral bodies VB so that its pair of first surfaces 11, 11 or its pair of second surfaces 12, 12 are in contact with the opposing surfaces of the vertebral bodies VB.
Next, the first member 10 is rotated to confirm that the distance between the vertebral bodies VB is the same as the distance W1 between the faces of the first member 10, and the condition between the vertebral bodies VB of the patient is confirmed.
If the patient is small and the space between the vertebral bodies VB cannot be widened, the second member 20 is moved along the square cross-sectional first member 10 so that the outer surfaces of the pair of side walls 22, 22 are in contact with the opposing surfaces of the vertebral body VB, and the first end 20a of the second member 20 is inserted into the adjacent vertebral body VB. After that, the square cross-sectional first member 10 is pulled out, and then a procedure is performed to remove the intervertebral disc between the vertebral bodies VB and the vertebral body VB itself, and a procedure is performed to place the implant IP.
In this case, the second member 20 used has a groove portion 20h with a square cross section. Specifically, the second member 20 used has a distance W2 between the inner surfaces of the pair of side walls 22, 22 that is equal to the distance W1, and a height T2 of the pair of side walls 22, 22 that is equal to the distance T1.
In addition, when the gap between the vertebral bodies VB is to be widened, the first member 10 with a square cross section is pulled out, and then the first end 10a of the first member 10 with a rectangular cross section is inserted between the adjacent vertebral bodies VB, and the first member 10 with a rectangular cross section is rotated to widen the gap between the adjacent vertebral bodies VB. Thereafter, the first member 10 with a rectangular cross section and the second member 20 suitable for this first member 10 are used to widen the gap between the adjacent vertebral bodies VB to a desired interval, and then a procedure is performed to remove the intervertebral disc between the vertebral bodies VB and the vertebral body VB itself, and a procedure is performed to place the implant IP. Note that, when the guide member 30 is used when inserting the first member 10 with a square cross section, the first member 10 with a square cross section is pulled out so as to leave the guide member 30, and the first end 10a of the first member 10 with a rectangular cross section is inserted into the gap between the adjacent vertebral bodies VB using the guide member 30.

The sizes of the first member 10 with a square cross section, the second member 20 with a square cross section, and the first member 10 and second member 20 with a rectangular cross section to be used are not particularly limited, and any size suitable for the physique of the patient to be treated can be used.

For example, for a patient of average Japanese build, using a first member 10 with a square cross section with sides measuring 8 mm, followed by a first member 10 with a rectangular cross section with distance T1 of 8 mm and distance W1 of 10 mm, and a second member 20 suitable for this first member 10 with a rectangular cross section, will make it easier to widen the gap between adjacent vertebral bodies VB to the desired distance.
Also, for a large Japanese patient, a first member 10 with a square cross section with one side measuring 8 mm is used, followed by a first member 10 with a rectangular cross section with a distance T1 of 8 mm and a distance W1 of 10 mm, and a second member 20 suitable for this first member 10 with a rectangular cross section. If a first member 10 with a rectangular cross section with a distance T1 of 10 mm and a distance W1 of 12 mm and a second member 20 suitable for this first member 10 with a rectangular cross section are then used, it becomes easier to widen the gap between adjacent vertebral bodies VB to a desired distance.
In the case of a small Japanese patient in which the space between the vertebral bodies VB cannot be widened, it is sufficient to use only the first member 10 having a square cross section with each side measuring 8 mm and the second member 20 having a square cross section that is suitable for this first member 10 having a square cross section.

<Regarding the first member 10>
In the first member 10, the connecting portions between the pair of first surfaces 11, 11 and the pair of second surfaces 12, 12 may be edged or chamfered. Also, the pair of first surfaces 11, 11 and the pair of second surfaces 12, 12 may be connected by a curved surface. Note that the cross section perpendicular to the axial direction of the first member 10 being substantially rectangular includes a concept in which the connecting portions between the pair of first surfaces 11, 11 and the pair of second surfaces 12, 12 are chamfered, and a concept in which the pair of first surfaces 11, 11 and the pair of second surfaces 12, 12 are connected by a curved surface.

Furthermore, the cross section of the first member 10 perpendicular to its axial direction is not limited to the substantially rectangular shape as described above. As described above, it may have any shape as long as it has a pair of first surfaces 11, 11 parallel to each other and a pair of second surfaces 12, 12 parallel to each other and having a different inter-surface distance from the pair of first surfaces 11, 11. For example, the cross section of the first member 10 perpendicular to its axial direction may be formed into a parallelogram with non-parallel sides of different lengths, a hexagon or octagon with some sides of different lengths from the other sides, or the like.

Furthermore, in the above example, a pair of inclined surfaces 11f, 11f is provided on the first end 10a of the first member 10, but it is not necessary to provide a pair of inclined surfaces 11f. Only the inclined surface 11f that is continuous with one of the first surfaces 11 may be provided on the first end 10a of the first member 10. Also, the inclined surface 10f may not be provided on the first end 10a of the first member 10. If the inclined surface 11f is provided on the first end 10a of the first member 10, it becomes easier to insert the first end 10a of the first member 10 between the vertebral bodies.

Furthermore, in the above example, the end face of the first end 10a of the first member 10 is formed into a flat surface perpendicular to the pair of first surfaces 11, 11 and/or the pair of second surfaces 12, 12, but it does not necessarily have to be perpendicular to the pair of first surfaces 11, 11 and/or the pair of second surfaces 12, 12, and it does not necessarily have to be a flat surface. In addition, the tip of the first end 10a of the first member 10 may be an edge that connects the pair of inclined surfaces 11f, 11f to each other.

Furthermore, when the guide member 30 is not used, the first member 10 does not need to have the through hole 10h or the recess 10d.

Furthermore, as shown in FIG. 24, a through hole h intersecting the axial direction of the first member 10 may be provided at the second end 10b of the first member 10. By forming such a through hole h, the first member 10 can be rotated around the axis of the first member 10 without using a special handle or the like, and the first member 10 can be pulled out between adjacent vertebrae VB or from the second member 20. For example, by inserting an axial member into the through hole h and rotating the axial member around the axis of the first member 10, the first member 10 can be rotated around the axis of the first member 10. In addition, by inserting an axial member into the through hole h and moving the axial member in the axial direction of the first member 10, the first member 10 can be pulled out between adjacent vertebrae VB or from the second member 20.

<Regarding the second member 20>
When the cross section perpendicular to the axial direction of the first member 10 is substantially rectangular, the second member 20 is formed such that the distance W2 between the inner surfaces of the pair of side walls 22, 22 has the above-mentioned length. In other words, when the pair of first surfaces 11, 11 and the pair of second surfaces 12, 12 are perpendicular to each other in the first member 10, the second member 20 is formed such that the distance W2 between the inner surfaces of the pair of side walls 22, 22 is the same as or slightly longer than the distance W1 between the pair of second surfaces 12, 12 of the first member 10.
On the other hand, even if the pair of first surfaces 11, 11 and the pair of second surfaces 12, 12 are non-orthogonal in a cross section perpendicular to the axial direction of the first member 10, the second member 20 may be formed to a size that allows the first member 10 and the second member 20 to move (slide) relatively. Specifically, the second member 20 may be formed so that the width of the first member 10 in a direction parallel to the pair of first surfaces 11, 11 and perpendicular to the axial direction and the distance between the inner surfaces of the pair of side walls 22, 22 of the second member 20 are approximately the same length.

The second member 20 may have a cross-sectional shape as shown in FIG. 16. For example, as shown in FIG. 16(A), the bottom wall 21 may be formed in a shape that is an arc (U-shaped cross section). As shown in FIG. 16(B), the second member 20 may have a shape that does not have one side wall 22, that is, a shape that has only the bottom wall 21 and one side wall 22 (L-shaped cross section). As shown in FIG. 16(C), the second member 20 may have a shape that has only one side wall 22 without the bottom wall 21 (V-shaped cross section). When the second member 20 has a shape as shown in FIG. 16(B), the function of maintaining the gap between the vertebral bodies VB against a force that narrows the gap between the adjacent vertebral bodies VB cannot be fully exerted. For this reason, when the second member 20 has a shape as shown in FIG. 16(B), it is desirable to maintain the gap between the adjacent vertebral bodies VB by, for example, separately placing an instrument for maintaining the gap between the adjacent vertebral bodies VB between the adjacent vertebral bodies VB. 16D, a shape (rectangular in cross section) may be provided with a ceiling wall 23 connecting the upper ends of a pair of side walls 22, 22. In this case, the width of the bottom wall 21 and the width of the ceiling wall 23 are the same, but the width of the pair of side walls 22, 22 may be different from the widths of the bottom wall 21 and the ceiling wall 23.

<Connection between the first member 10 and the second member 20>
A groove extending along the axial direction may be formed on the first surface 11 or the second surface 12 of the first member 10. In this case, if a rail-like protrusion or a simple protrusion extending along the axial direction of the groove portion 20h is provided on the bottom wall 21 or the side wall 22 of the groove portion 20h of the second member 20, the first member 10 can be moved along the axial direction of the groove portion 20h while being positioned relative to the second member 20.
In particular, when rail-shaped projections 20p extending along the axial direction of the groove 20h are formed on the bottom wall 21 or side wall 22 of the groove 20h (see FIGS. 15(A) and (B)), it is desirable to provide the implant IP with a groove that engages with the rail-shaped projection. Then, when placing the implant IP between the vertebral bodies through the groove 20h of the second member 20, the implant IP can be embedded in an appropriate position (i.e., the position where the first end 20a of the second member 20 is placed) without using a special tool.
Also, the same effect can be obtained by providing inwardly bent pieces 20r on the upper edges of the pair of side walls 22, 22 of the second member 20 (see FIG. 15(C)).

<Guide Member 30>
The shape of the stopper 32 of the guide member 30 is not limited to a sphere as described above, and may be any shape. For example, the stopper 32 may be a simple rod or plate-like member attached to the tip of the wire portion 31. Even in this case, the recess 10d of the first member 10 may be formed in a shape and size that can accommodate the stopper 32. Furthermore, if the stopper 32 can prevent the first member 10 from falling off, etc., the recess 10d does not need to be provided on the end surface of the first end portion 10a of the first member 10.

<About Shaver 40>
The shaver 40 may be a general shaver or may have a shape as shown in FIG. 13. That is, the shaver 40 shown in FIG. 13 has a shaft 41 and a handle 42 provided at one end of the shaft 41, and a cutting part 43 is provided at the other end of the shaft 41. The cutting part 43 has a substantially rectangular cross section, and cutting blades 43c are provided at the edge portions located on both sides of the cutting part 43. The cutting blades 43c are formed so as to perform a cutting function only when rotated in a predetermined direction. With this configuration, the cutting blades 43c are brought into contact with the vertebral body VB and the handle 42 is rotated to resect the vertebral body VB. For example, the handle 42 is rotated about 90 degrees left and right, forward and backward, to resect the vertebral body VB. On the other hand, the nerve side (exiting nerve root side) is not resected, so that the resection operation can be performed safely.
As described above, the shaver 40 may be provided with a through hole that passes through the axial direction and through which the guide member 30 can be inserted. In this case, if the central axis of the through hole and the central axis of the shaver 40 are coaxial, when performing a procedure in which the shaver 40 is rotated, the shaver 40 can be rotated around the central axis of the through hole. Moreover, since the shaver 40 can be prevented from moving in the axial direction of the through hole, the cutting edge 43c of the shaver 40 can be prevented from coming into contact with surrounding tissue. This makes it easier to prevent operational errors and the like.

<Regarding the handle 50>
The handle 50 is not particularly limited in shape or structure as long as it can rotate the first member 10 together with the handle 50 around the axis of the first member 10 when the handle 50 is attached to the second end 10b of the first member 10. For example, the handle 50 itself may be formed of a substantially rectangular member, and an engagement hole 50h that penetrates (or does not penetrate) the member may be provided. Then, when the handle 50 is rotated around the axis of the first member 10 with the second end 10b of the first member 10 inserted into the engagement hole 50h, the first member 10 may be rotated around the axis together with the handle 50. In this case, the shape of the engagement hole 50h is not particularly limited, and it is sufficient that the shape is such that the movement of the handle 50 around the axis of the first member 10 relative to the first member 10 is limited. For example, if the cross-sectional shape of the engagement hole 50h and the cross-sectional shape of the second end 10b of the first member 10 are substantially the same shape and size, the above-mentioned function can be exhibited. Specifically, the above-mentioned function can be achieved by forming the cross-sectional shape of the engagement hole 50h and the cross-sectional shape of the second end 10b of the first member 10 into a rectangular cross-section such as a rectangle or a square, or a polygonal cross-section such as a triangle or a pentagon (see Figures 4, 18, and 25 (B)).

Also, a pair of engagement grooves 10g, 10g recessed from the pair of first surfaces 11, 11 or the pair of second surfaces 12, 12 may be formed in the second end portion 10b of the first member 10 (see FIGS. 20 and 21), and an engagement portion 51 that engages with the pair of engagement grooves 10g, 10g may be provided in the handle 50. By providing such a pair of engagement grooves 10g, 10g in the second end portion 10b of the first member 10 and providing the engagement portion 51 in the handle 50, it becomes easier to pull out the first member 10 from between the vertebral bodies VB or from the second member 20.

The shape of the pair of engagement grooves 10g, 10g and the shape of the engagement portion 51 are not particularly limited, and they may be formed in such a shape that when the two are engaged, the axial movement of the handle 50 relative to the first member 10 is restricted. In other words, when the handle 50 is moved in the axial direction of the first member 10, the first member 10 can be moved in the axial direction together with the handle 50. For example, a pair of engagement grooves 10g, 10g recessed from a pair of second surfaces 12, 12 are formed in the second end portion 10b of the first member 10 (see FIG. 17). In this case, the above function can be exhibited by providing a pair of engagement protrusions 51p, 51p as the engagement portion 51, and making the distance between the inner surfaces of the pair of engagement protrusions 51p, 51p longer than the distance between the inner bottom surfaces of the pair of engagement grooves 10g, 10g and shorter than the distance between the pair of first surfaces 12, 12.

<Regarding the handle 50B>
As the handle, a handle 50B having a shape as shown in FIG. 25(A) or FIG. 27(A) may be used.
This handle 50B has an approximately T-shape and has an axis portion 51B connected to the second end portion 10b of the first member 10, and a retaining portion 52B provided at the base end of this axis portion 51B.
The holding portion 52B is a member having a portion a extending from the base end of the shaft portion 51B so as to intersect with the axial direction. The shape of the holding portion 52B is not particularly limited as long as it is formed into a shape that allows the practitioner to easily hold the handle 50B. In particular, it is sufficient that the shape allows the practitioner to easily rotate the handle 50B around the axis of the first member 10, as described below, even in a state in which the first end portion 10a of the first member 10 is inserted between the vertebrae VB.
The shaft portion 51B has an engagement hole 51h (see FIG. 27) at its tip into which the second end 10b of the first member 10 is inserted. This engagement hole 51h is formed so that when the second end 10b of the first member 10 is inserted, the rotation of the first member 10 relative to the shaft portion 51B is fixed. In other words, the engagement hole 51h of the shaft portion 51B is formed so that when the handle 50B is rotated around the axis of the first member 10, the first member 10 also rotates around the axis together with the handle 50B. The shape of the engagement hole 51h is not particularly limited, and it may be shaped so that, like the handle 50, when the engagement hole 51h engages with the second end 10b of the first member 10, the movement of the handle 50 relative to the first member 10 around the axis of the first member 10 is limited.
In addition, when the handle 50B is used, a recessed portion g may be provided at the second end 10b of the first member 10 as shown in FIG. 25(B). In this case, an engagement member b that engages with the recessed portion g when the handle 50B is connected to the first member 10 is provided in an engagement hole 51h of the shaft portion 51B of the handle 50B. If such an engagement member b is provided, when the engagement hole 51h of the shaft portion 51B is inserted into the second end 10b of the first member 10, the engagement member b engages with the recessed portion g, thereby fixing the movement of the handle 50B in the axial direction of the first member 10. Then, when the handle 50B is moved in the axial direction of the first member 10 while the handle 50B is connected to the first member 10, the first member 10 can be pulled out between the adjacent vertebrae VB or from the second member 20. The structure of the engagement member b is not particularly limited. For example, a sphere can be used as the engagement member b as shown in FIG. 27(B) and (C). When such an engaging member b is employed, it is provided so that it cannot move in the axial direction of the engaging hole 51h but can move in the radial direction of the engaging hole 51h, and is biased toward the engaging hole 51h by a spring or the like. This reduces the resistance when the engaging hole 51h of the shaft portion 51B is inserted into the second end 10b of the first member 10, while allowing the second end 10b of the first member 10 to be engaged with the engaging hole 51h.
Furthermore, when using a guide member 30 when inserting the first member 10 between adjacent vertebral bodies VB, it is necessary to form a through hole 50g in the handle 50B to insert the guide member 31 of the guide member 30 along the axial direction of the shaft portion 51B.
The handle 50B may also be used for the shaver 40. That is, instead of the handle 42 of the shaver 40 shown in FIG. 13, the handle 50B may be detachably attached to the shaft 41 of the shaver 40 (see FIG. 26(A)). In this case, one end 41b of the shaft 41 of the shaver 40 may be formed so that when the handle 50B is rotated around the axis of the shaft 41, the shaft 41 also rotates around the axis together with the handle 50B. For example, it is preferable that the one end 41b of the shaft 41 of the shaver 40 is formed in the same cross-sectional shape as the second end 10b of the first member 10 to which the handle 50B is connected (see FIG. 26(B)). When providing the above-mentioned engaging member b on the shaft portion 51B of the handle 50B, it is desirable to provide a recessed portion on one end 41b of the shaft portion 41 of the shaver 40, like the second end portion 10b of the first member 10, which engages with the engaging member b; however, it is not necessarily necessary to provide a recessed portion as shown in Figure 26 (B).

<Hammer 60>
When inserting the first end 10a of the first member 10 between the vertebral bodies VB, if there is a large resistance to insertion, it is difficult for the practitioner to push the first member 10 in. In that case, the end face of the second end 10b of the first member 10 is struck with a hammer or the like to insert the first end 10a of the first member 10 between the vertebral bodies VB.
However, when the wire portion 31 of the guide member 30 is inserted through the first member 10, the wire portion 31 gets in the way when the end face of the second end portion 10b of the first member 10 is struck with a hammer or the like.
Therefore, when striking the end face of the second end 10b of the first member 10 with the wire portion 31 of the guide member 30 inserted through the first member 10, it is desirable to use a hammer 60 having the following shape.

As shown in FIG. 19, the hammer 60 has a handle 61 that is held by the practitioner, and a hammer head 62 provided at the axial end of the handle 61 .

The hammer head 62 is provided at the axial end of the handle 61 so that its central axis is perpendicular to the axial direction of the handle 61. The hammer head 62 is provided with striking surfaces 62s, 62s for striking the first member 10 on both axial end faces. The striking surfaces 62s, 62s are provided with flat surfaces perpendicular to the central axis of the hammer head 62 at positions where the central axis of the hammer head 62 passes through the striking surfaces 62s, 62s.

The hammer head 62 has an insertion groove 62c in the middle between the striking surfaces 62s, 62s in the central axis direction. The insertion groove 62c is a groove having an opening in a surface that intersects with the striking surface 62s of the hammer head 62, in other words, a surface formed to surround the central axis direction of the hammer head 62 (hereinafter, sometimes referred to as the side surface of the hammer head 62). The insertion groove 62c is formed so that its axial direction (the direction perpendicular to the paper surface in FIG. 19(A)) intersects with the central axis direction of the hammer head 62. For example, in FIG. 19, the insertion groove 62c is formed so that its axial direction is perpendicular to the central axis direction of the hammer head 62. The insertion groove 62c is formed so that its width (the length in the vertical direction of the paper surface in FIG. 19(A)) is longer than the shaft diameter of the wire portion 31. Furthermore, this insertion groove 62c is formed so that its depth (the length in the left-right direction of the paper in Figure 19 (A)) is slightly longer (for example, longer by the length of the radius of the wire portion 31) than the distance from the surface of the hammer head 62 to the central axis (hereinafter sometimes referred to as the radius of the hammer head 62).

Further, the hammer head 62 is formed with a guide groove 62g that communicates between the striking surfaces 62s, 62s. For example, in FIG. 19, the guide groove 62g is formed so that its axial direction is parallel to the central axis of the hammer head 62. This guide groove 62g is a groove recessed from the side surface of the hammer head 62, that is, a groove having an opening on the side surface of the hammer head 62. This guide groove 62g is formed by a first guide groove 62a that communicates between one striking surface 62s and the insertion groove 62c, and a second guide groove 62b that communicates between the other striking surface 62s and the insertion groove 62c. The first guide groove 62a and the second guide groove 62b are formed at a position where the opening formed on the side surface of the hammer head 62 is rotated 180 degrees around the central axis of the hammer head 62. That is, the first guide groove 62a and the second guide groove 62b are formed on the side surface of the hammer head 62 so as to be recessed from opposite directions toward the central axis of the hammer head 62 from a position rotated 180 degrees around the central axis of the hammer head 62 (see FIG. 19(B)). Moreover, the first guide groove 62a and the second guide groove 62b are formed so that when the wire portion 31 is brought into contact with the inner bottom surface of each, the central axis of the wire portion 31 substantially coincides with the central axis of the hammer head 62. The central axis of the wire portion 31 substantially coincides with the central axis of the hammer head 62 includes cases where there is a slight deviation in the radial direction of the hammer head 62, and cases where there is a slight inclination between the central axis of the wire portion 31 and the central axis of the hammer head 62.

The insertion groove 62c and the second guide groove 62b are formed so that their respective inner bottom surfaces are located at approximately the same position in the radial direction of the hammer head 62. The fact that the inner bottom surfaces of the insertion groove 62c and the second guide groove 62b are located at approximately the same position in the radial direction of the hammer head 62 also includes the case where there is a slight deviation in the radial direction of the hammer head 62.

Since the hammer 60 has the shape described above, by doing as follows, even when the wire portion 31 of the guide member 30 is inserted into the first member 10, the end face of the second end 10b of the first member 10 can be struck with a hammer or the like by the striking surface 62s of the hammer head 62 of the hammer 60.

20A, first, the wire portion 31 is inserted into the insertion groove 62c of the hammer head 62 so that the axial direction of the wire portion 31 is parallel to the axial direction of the insertion groove 62c. Then, the wire portion 31 is disposed so as to contact the inner bottom surface of the insertion groove 62c.

Next, the hammer 60 is rotated around the axis of the handle portion 61. In other words, the hammer 60 is rotated around an axis perpendicular to the central axis of the hammer head 62. Then, since the inner bottom surfaces of the insertion groove 62c and the second guide groove 62b are formed to be at approximately the same position in the radial direction of the hammer head 62, the wire portion 31 can be disposed in the groove 62a of the guide groove 62g and the second guide groove 62b (FIG. 20(B)).

Then, when the wire portion 31 comes into contact with the inner bottom surfaces of both the first guide groove 62a and the second guide groove 62b (FIG. 21(A)), the central axes of the wire portion 31 and the hammer head 62 are aligned. In this state, if the hammer head 62 is moved along the wire portion 31 toward the end face of the second end portion 10b of the first member 10, the end face of the second end portion 10b of the first member 10 can be struck by the striking surface 62s of the hammer head 62 (FIG. 21(B)).

The hammer head 62 does not need to have the insertion groove 62c. When the insertion groove 62c is not provided, the guide groove 62g may be formed on the side surface of the hammer head 62 so that an opening is formed between the striking surfaces 62s, 62s. Then, the hammer head 62 is arranged so that the axial direction of the guide groove 62g is parallel to the axial direction of the wire portion 31 of the guide member 30, and the wire portion 31 is inserted into the guide groove 62g from the opening. Then, the axial direction of the hammer head 62 and the axial direction of the wire portion 31 can be aligned, so that the hammer head 62 can be moved along the wire portion 31. Therefore, the striking surface 62s of the hammer head 62 of the hammer 60 can accurately strike the end surface of the second end portion 10b of the first member 10.

Furthermore, the shape of the hammer head 62 is not particularly limited as long as the striking surface 62s is formed on the end surface in the axial direction. The hammer head 62 may be formed in a cylindrical shape with a cylindrical side surface, or may have a portion recessed from the side as shown in Fig. 19. If the hammer head 62 is provided with a portion recessed from the side as shown in Fig. 19, the weight of the hammer head 62 and the hammer 60 can be reduced. This has the advantage of improving the ease of handling of the hammer 60.
Furthermore, the striking surface 62s may be provided on both end surfaces of the hammer head 62 in the central axis direction, or the striking surface 62s may be provided on only one end surface.

<Supply device 70>
In the case of the second member 20 of the surgical instrument 1 of this embodiment, a route can be formed that connects from outside the patient's body to between the vertebral bodies VB, but because the upper part of the groove portion 20h is open, it is difficult to supply bone to be transplanted between the vertebral bodies VB through the route. Therefore, when a route that connects from outside the patient's body to between the vertebral bodies VB is formed using the second member 20, the bone to be transplanted can be more reliably supplied between the vertebral bodies VB by using a supply instrument 70 described below.

As shown in FIG. 22, the supply tool 70 has a funnel-shaped portion 71 and a tubular portion 72 connected to the funnel-shaped portion 71 .

The funnel-shaped portion 71 is a member having an opening at the top and a supply space 71h in which the bone to be transplanted is accommodated. The funnel-shaped portion 71 has a main body portion 71a having a conical bottom surface and a wall 71b extending from the upper end of the main body portion 71a. The area surrounded by the conical bottom surface of the main body portion 71a and the inner surface of the wall 71b forms the supply space 71h. In addition, a communication hole 71c is formed in the bottom surface of the main body portion 71a of the funnel-shaped portion 71, which communicates between the supply space 71h and the outside. The communication hole 71c is formed at a position shifted in the radial direction of the main body portion 71a from the central axis 71s of the funnel-shaped portion 71.

The tubular portion 72 is a hollow tubular member, and has an introduction passage 72h therein that communicates between the base end and the tip end. The base end of the tubular portion 72 is connected to the outer surface of the main body 71a of the funnel-shaped portion 71. Specifically, the tubular portion 72 is connected to the main body 71a of the funnel-shaped portion 71 so that the supply space 71h of the main body 71a of the funnel-shaped portion 71 communicates with the introduction passage 72h through a communication hole 71c formed in the main body 71a of the funnel-shaped portion 71. The tubular portion 72 is provided so that its axial direction, that is, the central axis 72s of the introduction passage 72h is inclined with respect to the central axis 71s of the funnel-shaped portion 71. For example, the angle θ between the central axis 72s of the introduction passage 72h and the central axis 71s of the funnel-shaped portion 71 is formed to be about 30 to 60 degrees, preferably 45 degrees.

The tubular portion 72 is formed so that its outer diameter is equal to or slightly shorter than the distance W2 between the inner surfaces of the pair of side walls 22, 22 of the groove portion 20h of the second member 20. In other words, the tubular portion 72 is formed so that it can be accommodated in the groove portion 20h of the second member 20 with the central axis 72s parallel to the axial direction of the groove portion 20h of the second member 20. Moreover, the tubular portion 72 is formed so that it can move along the axial direction of the groove portion 20h of the second member 20 while being accommodated in the groove portion 20h of the second member 20.

Since the supplying instrument 70 has the above-mentioned structure, the bone to be grafted can be supplied between the vertebrae VB by the supplying instrument 70 in the following manner.

First, the first end 20a of the second member 20 is placed between the vertebrae VB, and nothing is placed in the groove 20h of the second member 20 (see FIG. 9B). In this state, the tubular portion 72 of the supplying instrument 70 is accommodated in the groove 20h of the second member 20 with its central axis 72s parallel to the axial direction of the groove 20h of the second member 20. Then, by moving the tubular portion 72 of the supplying instrument 70 along the axial direction of the groove 20h of the second member 20, the tip of the tubular portion 72 can be placed between the vertebrae VB (see FIG. 23A).

Next, when the bone to be grafted is supplied into the supply space 71h of the funnel-shaped portion 71 of the supply instrument 70, the bone supplied into the supply space 71h of the funnel-shaped portion 71 is supplied between the vertebrae VB through the introduction passage 72h.

As described above, by using the supplying device 70, the bone to be grafted can be supplied between the vertebrae VB. Moreover, since the central axis 72s of the tubular portion 72 of the supplying device 70 is inclined relative to the central axis 71s of the funnel-shaped portion 71, the bone to be grafted can be stably held in the supplying space 71h of the funnel-shaped portion 71. In other words, when the tubular portion 72 is placed in the groove portion 20h of the second member 20, even if the groove portion 20h of the second member 20 is inclined relative to the horizontal, the central axis 72s of the tubular portion 72 is inclined relative to the central axis 71s of the funnel-shaped portion 71, so that the bone to be grafted can be easily held in the supplying space 71h of the funnel-shaped portion 71.

When bone is supplied between the vertebrae VB through the introduction passage 72h of the tubular portion 72, the introduction passage 72h can be moved by the weight of the bone. However, in order to perform the treatment reliably in a short time, it is preferable to push the bone in the introduction passage 72h between the vertebrae VB by using a pushing member 75 having an axial member 75a that can be inserted into the introduction passage 72h, as shown in Figures 22 and 23. In this case, it is preferable to form an insertion hole 71g for inserting the axial member 75a of the pushing member 75 at the position where the wall 71b of the funnel-shaped portion 71 and the central axis of the communication hole 71c intersect. If such an insertion hole 71g is formed, it becomes easier to push the bone in the introduction passage 72h between the vertebrae VB by the pushing member 75.

In addition, the angle between the central axis 72s of the tubular portion 72 and the central axis 71s of the supply space 71h of the funnel-shaped portion 71 is not particularly limited as long as they are parallel to each other. However, if the angle θ between the two is about 30 to 60 degrees, the bone to be transplanted can be easily held in a stable state in the supply space 71h of the funnel-shaped portion 71, which is preferable since it makes it easier to perform the procedure of supplying the bone to be transplanted between the vertebrae VB. In particular, if the angle θ between the two is 45 degrees, when the tubular portion 72 is placed in the groove portion 20h of the second member 20 in a state in which a route communicating from outside the patient's body to the vertebrae VB is formed by the second member 20, the central axis 71s of the supply space 71h of the funnel-shaped portion 71 can be maintained in a state close to vertical. Then, when the bone to be transplanted is supplied between the vertebrae VB, the bone to be transplanted can be easily held in a stable state by the supply space 71h of the funnel-shaped portion 71.

Moreover, the tubular portion 72 does not necessarily have to be formed so that its outer diameter is equal to or slightly shorter than the distance W2 between the inner surfaces of the pair of side walls 22, 22 of the groove portion 20h of the second member 20. In other words, the outer diameter of the tubular portion 72 may be larger than the distance W2 between the inner surfaces of the pair of side walls 22, 22 of the groove portion 20h of the second member 20. Even in this case, if the tip of the tubular portion 72 is positioned between the vertebrae VB after the second member 20 is removed, the bone to be transplanted can be supplied between the vertebrae VB by the supply instrument 70.

The surgical instrument of the present invention is suitable as an instrument for forming or maintaining intervertebral space in surgeries or procedures such as intervertebral fixation, interbody enlargement, intervertebral disc curettage, and interbody foreign body insertion.

LIST OF SYMBOLS 1 Surgical instrument 10 First member 10a First end 10b Second end 10g Engagement groove 11 First surface 11f Inclined surface 12 Second surface g Recessed portion 20 Second member 20h Groove portion 21 Bottom wall 22 Side wall 30 Guide portion 31 Wire portion 32 Stopper 50 Handle 50h Engagement hole 51 Engagement portion 50B Handle 50g Through hole 51B Shaft portion 52B Holding portion 51h Engagement hole b Engagement member 60 Hammer 62 Hammer head 62g Guide groove 62a First guide groove 62b Second guide groove 62c Insertion groove 70 Supply instrument 71 Funnel-shaped portion 71h Supply space 71s Central axis 72 Tubular portion 72h Introduction passage 71g Insertion port C Spinal cord V Vertebra VB Vertebral body d Intervertebral disc IP Implant TR Cambin's triangle

Claims (15)

1. An instrument for use in intervertebral surgery of the spine, comprising:
A first member having a pair of first surfaces extending in a first direction and parallel to each other, and a pair of second surfaces intersecting the pair of first surfaces extending in the first direction and parallel to each other;
a second member having a groove for receiving the first member and communicating between a first end and a second end,
The groove of the second member is
the first member and the second member are formed so as to be relatively movable along the axial direction of the groove portion in a state in which the first direction of the first member and the axial direction of the groove portion of the second member are parallel to each other,
The first member includes:
a through hole is formed between an end face of a first end portion in the first direction and an end face of a second end portion in the first direction,
a guide member having a wire portion inserted into the through hole,
The first end of the wire portion of the guide member is provided with
A surgical instrument comprising: a stopper provided to limit movement of the first member along a wire portion of the guide member. 1. An instrument for use in intervertebral surgery of the spine, comprising:
A first member having a pair of first surfaces extending in a first direction and parallel to each other, and a pair of second surfaces intersecting the pair of first surfaces extending in the first direction and parallel to each other;
a second member having a groove for receiving the first member and communicating between a first end and a second end,
The groove of the second member is
The groove has a bottom wall extending along an axial direction of the groove, and a pair of side walls extending along the axial direction of the groove and parallel to each other,
The second member is
a distance between the inner surfaces of the pair of side walls is formed to a length that allows the first member and the second member to move relatively along the axial direction of the groove portion in a state where the first direction of the first member and the axial direction of the groove portion of the second member are parallel to each other,
The first member includes:
a through hole is formed between an end face of a first end portion in the first direction and an end face of a second end portion in the first direction,
a guide member having a wire portion inserted into the through hole,
The first end of the wire portion of the guide member is provided with
A surgical instrument comprising: a stopper provided to limit movement of the first member along a wire portion of the guide member. The first end of the first member in the first direction has an end surface
3. The surgical instrument according to claim 1, further comprising a recess for receiving a stopper of the guide member. a hammer for driving the first member between vertebrae of the spine;
The hammer head of the hammer has
a guide groove recessed from a surface intersecting both end faces of the hammer head so as to communicate between both end faces of the hammer head;
The guide groove is
4. The surgical instrument according to claim 1, wherein the width of said wire portion is the same as the shaft diameter of said wire portion of said guide member. The hammer head of the hammer has
An insertion groove having a width greater than the shaft diameter of the wire portion of the guide member is formed in a surface intersecting both end faces of the hammer head,
The insertion groove is
The axial direction of the guide groove is formed to intersect with the axial direction of the guide groove.
The guide groove is
a first guide groove formed between the insertion groove and one end surface of the hammer head;
a second guide groove formed between the insertion groove and the other end surface of the hammer head,
The first guide groove is
an opening formed on a surface intersecting both end faces of the hammer head is formed at a position rotated 180 degrees around the central axis of the hammer head with respect to an opening formed on a surface of the second guide groove intersecting both end faces of the hammer head,
5. The surgical instrument according to claim 4. The groove portion of the second member is
the first member and the second member are formed so as to be relatively movable along the axial direction of the groove portion in a state in which the first direction of the first member and the axial direction of the groove portion of the second member are parallel to each other,
The second end of the first member has
An engagement groove is formed recessed from the pair of first surfaces or the pair of second surfaces,
A handle for operating the first member is provided,
The handle has:
an engagement hole through which the second end of the first member is inserted;
an engagement portion that engages with the engagement groove,
The engagement hole of the handle is
When the second end of the first member is inserted into the engagement hole, the engagement hole is formed in a shape that limits movement of the handle relative to the first member around the axis of the first member,
The engagement portion of the handle is
6. The surgical instrument according to claim 1, wherein the engaging portion is formed in a shape that limits axial movement of the handle relative to the first member when the engaging portion is engaged with the engaging groove. The groove portion of the second member is
the first member and the second member are formed so as to be relatively movable along the axial direction of the groove portion in a state in which the first direction of the first member and the axial direction of the groove portion of the second member are parallel to each other,
The second end of the first member has
An engagement groove is formed recessed from the pair of first surfaces and/or the pair of second surfaces,
A handle for operating the first member is provided,
The handle has:
an engagement hole through which the second end of the first member is inserted;
an engagement member that engages with the engagement groove;
The engagement hole of the handle is
When the second end of the first member is inserted into the engagement hole, the engagement hole is formed in a shape that limits movement of the handle relative to the first member around the axis of the first member,
The engagement member of the handle comprises:
The surgical instrument according to any one of claims 1 to 5, characterized in that when the second end of the first member is inserted into the engagement hole, it engages with the engagement groove of the second end of the first member, thereby limiting axial movement of the handle relative to the first member. The groove portion of the second member is
the first member and the second member are formed so as to be relatively movable along the axial direction of the groove portion in a state in which the first direction of the first member and the axial direction of the groove portion of the second member are parallel to each other,
a supplying device for supplying bone to be grafted between vertebrae of the spine;
The supply device comprises:
a funnel-shaped portion having a supply space in which the bone to be grafted is accommodated, the inner surface of which is formed into a conical surface;
a tubular portion having an introduction passage communicating with the supply space of the funnel portion,
The tubular portion is
6. The surgical instrument according to claim 1 , wherein the axial direction of the funnel-shaped portion is inclined with respect to a central axis of the supply space of the funnel-shaped portion. The delivery device comprises:
8. The surgical instrument according to claim 7, wherein a wall defining said supply space has an insertion hole for inserting a shaft-shaped member into the introduction passage of said tubular portion. 10. The surgical instrument according to claim 8, wherein an angle between the tubular portion and a central axis of the supply space in the funnel-shaped portion is 30 to 60 degrees. The tubular portion is
11. The surgical instrument according to claim 8, 9 or 10, characterized in that it is formed so that it can be housed in the groove of the second member with its axis parallel to the axial direction of the groove of the second member, and so that it can move along the axial direction of the groove of the second member in that state. The first member is
a distance between the pair of first surfaces is shorter than a distance between the pair of second surfaces,
The groove portion of the second member is
The groove has a bottom wall extending along an axial direction of the groove, and a pair of parallel side walls extending along the axial direction of the groove,
The second member is
12. The surgical instrument according to claim 2, wherein the first member and the second member are formed so as to be movable relative to each other with the inner surfaces of the pair of side walls facing the pair of second surfaces. The groove portion of the second member is
The groove has a bottom wall extending along an axial direction of the groove, and a pair of parallel side walls extending along the axial direction of the groove,
Between the inner surfaces of the pair of side walls of the second member,
The surgical instrument according to any one of claims 2 to 12, characterized in that the first member is formed to have a length equal to a length in a direction parallel to the pair of first surfaces and perpendicular to the first direction. The first member is
The surgical instrument according to any one of claims 1 to 13, wherein the pair of first surfaces and the pair of second surfaces are formed to be perpendicular to each other. The first member is
15. The surgical instrument according to claim 1, wherein an inclined surface is formed at a first end in the first direction, the inclined surface being inclined from one of the first surfaces toward the other of the first surfaces.

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