Therapeutic instrument

Abstract

The present invention provides a therapeutic instrument including a vertebral drilling guide and a bone drilling instrument, the therapeutic instrument being configured as follows. The vertebral drilling guide is a hollow cylindrical shape along a central axis, with a first scoop part opening in a direction perpendicular to the central axis at the leading-end side along the central axis and a second scoop part opening in the opposite direction of the perpendicular direction at the base-end side along the central axis. The bone drilling instrument is rod-shaped, is smoothly curved in the perpendicular direction along a central axis, and when inserted into the vertebral drilling guide along the central axis from the distal end of the second scoop part of the vertebral drilling guide, a leading-end portion thereof protrudes out of an opening in the first scoop part. This makes it possible to provide a safe therapeutic instrument that enables precise drilling of an intended area all the way inside the vertebral body while minimizing skin incision in percutaneous vertebroplasty of fractures and prophylactic reinforcement of the vertebral body with bone cement.

Description

treatment equipment

[0001] The present invention relates to a spinal treatment device for filling the spine (also called "vertebral body") with bone cement, and is particularly suitable for use in surgery to treat fractures or to stabilize and reinforce the spine before inserting an artificial intervertebral disc.

[0002] One of the spinal treatment methods is percutaneous vertebroplasty, which involves inserting a balloon catheter into the fracture site, expanding the balloon to create a space for cement filling, and then filling the space with bone cement.

[0003] Patent Literature 1 discloses a method for determining the size and / or placement of a screw or instrument in the pedicle of a selected spinal region during a surgical procedure, which involves generating a full-size three-dimensional image of the vertebrae of the spinal region, hollowing out the vertebrae in the three-dimensional image according to the cortical wall thickness selected by the surgeon, determining the isthmus of each pedicle, and then determining the ideal diameter, length, and / or trajectory of the pedicle screw or instrument.

[0004] Patent Document 2 discloses a method and device for treating intervertebral disc diseases. The method for performing transpedicular discectomy disclosed in this patent document includes the steps of forming a transpedicular channel through the pedicle of a vertebra to the vertebral body, inserting a flexible awl through the transpedicular channel and forming an angle of approximately 90 degrees with the flexible awl to penetrate the vertebral body and form a channel into the intervertebral disc, and removing a portion of the intervertebral disc with a laser device.

[0005] Special table 2008-537496 publication Special table 2007-526001 publication

[0006] The greatest drawback of percutaneous vertebroplasty is the high incidence of adjacent vertebral fractures after surgery (adjacent vertebral fractures). Recent studies have revealed the risk of adjacent vertebral fractures after surgery. However, there is no optimal treatment device for reinforcing adjacent vertebrae to prevent adjacent vertebral fractures during the initial percutaneous vertebroplasty. The reasons for this are as follows: First, if a cavity for filling with bone cement is created in the adjacent vertebra using a balloon catheter, as in the fractured vertebra, by high-pressure balloon expansion, there is a risk of destroying the cortical bone (shell) of the adjacent vertebra. Destroying the cortical bone (shell) is the exact opposite of reinforcing the vertebra, thus defeating the purpose. Second, even if a balloon catheter can be expanded at the center of the vertebra without destroying the cortical bone (shell) and bone cement can be injected into the center, it is difficult to safely inject bone cement into every corner of the normal vertebra. The third point is that if bone cement is injected into the vertebrae using something like a syringe without creating a sufficient cavity for filling with bone cement, the bone cement may not fill the intended location in the vertebral body due to the structure and characteristics of the body, and the liquid bone cement may enter the bloodstream from the bone and flow into the adjacent vena cava, and then into the pulmonary artery, where it hardens, potentially causing a fatal pulmonary embolism. This has also been reported in previous literature.

[0007] The present inventors have discovered a problem in that there is no suitable treatment instrument that can accurately drill every corner of the inside of the vertebral body at the intended location as a pretreatment for replacing and reinforcing the inside of the vertebra with bone cement without destroying the normal shape of the vertebra. This problem can be discussed in the following three points.

[0008] The first problem is that it is anatomically difficult to accurately drill and excavate every corner of the vertebral body near the lower end plate to form a cavity.

[0009] Patent Document 1 discloses a straight cannula with grooves that allows the introduction and advancement of a balloon catheter that is pre-bent or can be manually bent to a desired angle, and that allows the balloon to be positioned at the center of the vertebral body (see paragraph 0124, Figures 38a-b, 39a-b, etc.).

[0010] However, this technique is intended to position the balloon cutter at the center of the vertebral body, and cannot be applied to an instrument for accurately drilling every corner of the vertebral body at the intended location. Because the cannula is linear, the tip of the drilling tool, which is the drilling point, cannot be accurately guided to the intended location. Although it can be manually bent to a desired angle, the bending point is only at the proximal end of the groove of the linear cannula, and once inside the vertebral body after penetrating the pedicle, it can only be moved linearly along the cannula. Therefore, it is anatomically difficult to accurately drill and drill every corner of the vertebral body near the lower end plate to form a cavity.

[0011] Here, proximal is a medical term referring to the side closer to the centerline of the patient's body, and distal is the side further away. The cement is a medical bone cement, primarily composed of calcium phosphate and polymethylmethacrylate, which hardens over time.

[0012] The second problem is that there is no minimally invasive treatment device that can solve the above problems.

[0013] As shown in Figure 38b of Patent Document 1, the surgeon's hands holding the cannula 600 and balloon catheter 704 are widely exposed, necessitating a large incision in the patient's skin. Furthermore, the vertebral arch structure, which is the insertion site of the cannula, must be fully exposed during surgery. In other words, the skin must be incised and surgically deployed to fully expose the deepest part of the sulcus (the vertebral side). Therefore, even if the above-mentioned problems can be solved, this device cannot be considered a minimally invasive treatment device.

[0014] The third problem is the lack of a safe treatment instrument that can solve the first and second problems. The flexible awl disclosed in Patent Document 2 is inserted into the vertebral body through a straight retention tube inserted into a transpedicular channel formed through the pedicle of the vertebra to the vertebral body, and is then curved inside the vertebral body so that the flexible drilling tip reaches the drilling site (see Figures 30 to 32, etc.). This allows precise drilling of the intended site deep inside the vertebral body, and since the path from the skin to the pedicle is linear, it is expected that the amount of skin incision can be kept to a minimum.

[0015] However, the inventors have noticed that instruments introduced into a vertebral body along a linear retention tube and deformed within the vertebral body must be returned to the linear cylindrical shape of the retention tube when removed. However, there is a risk that the deformation may not return to its original shape depending on the condition of the internal bone, making removal difficult. Specifically, a therapeutic instrument that has plasticity and deforms within the vertebral body and is inserted into a vertebra may become caught on bone fragments, preventing the plasticity from returning to its original shape within the vertebra. In such a case, if the instrument does not return to its linear retention tube and an attempt is made to forcibly remove it, there is a risk that the therapeutic instrument may break inside the body, resulting in the placement of a foreign object. Therefore, even though the plastic therapeutic instrument disclosed in Patent Document 2 can solve the first and second problems described above, it cannot be considered a safe therapeutic instrument.

[0016] It should be noted that "safety" as used herein is not limited to the ease of removal. The known treatment instrument described in the above-mentioned Patent Document 1 uses three-dimensional images to ensure safety. Conversely, it should be understood that without the use of such three-dimensional images, there is an inherent risk of perforating an unintended area, and safety is not guaranteed by the treatment instrument itself.

[0017] As described above, although there are means capable of resolving each of the first to third problems, a treatment device capable of resolving all of them simultaneously has not yet been developed.

[0018] An object of the present invention is to provide a safe treatment instrument that can accurately excavate every corner of the inside of a vertebral body at the intended location while minimizing incision of the skin.

[0019] The means for solving these problems will be described below, but other problems and novel features will become apparent from the description of this specification and the accompanying drawings.

[0020] According to one embodiment of the present invention, the following is true.

[0021] That is, the treatment instrument includes a vertebral body drilling guide and a bone drilling instrument, and is configured as follows: The vertebral body drilling guide is hollow and cylindrical along a central axis, and has a first spatula part that opens in a direction perpendicular to the central axis at its tip end along the central axis, and a second spatula part that opens in a direction opposite to the perpendicular direction at its base end along the central axis. The bone drilling instrument is rod-shaped and smoothly curves in the perpendicular direction along the central axis, and when inserted into the vertebral body drilling guide along the central axis from the distal end of the second spatula part of the vertebral body drilling guide, its tip portion protrudes from the opening of the first spatula part.

[0022] The effects obtained by the above-described embodiment can be briefly explained as follows: In other words, a safe treatment instrument can be provided that can accurately excavate the inside of a vertebral body to every corner at the intended location while minimizing the incision of the skin in percutaneous vertebral body plasty for fractures or surgery for preventively reinforcing a vertebral body with bone cement.

[0023] FIG. 1 is an explanatory perspective view showing an example of the configuration of a treatment instrument according to a first embodiment. FIG. 2 is an explanatory perspective view showing an example of the configuration of a treatment instrument according to a second embodiment. FIG. 3 is an explanatory perspective view showing an example of the configuration of a vertebral body perforation guide and an inner cylindrical needle according to a third embodiment. FIG. 4 is an explanatory schematic view showing an example of the configuration of a vertebral body perforation guide according to a fourth embodiment. FIG. 5A is a cross-sectional view showing the cross-sectional shape (circle) of a vertebral body perforation guide according to one embodiment. FIG. 5B is a cross-sectional view showing the cross-sectional shape (oval) of a vertebral body perforation guide according to one embodiment. FIG. 5C is a cross-sectional view showing the cross-sectional shape (ellipse) of a vertebral body perforation guide according to one embodiment. FIG. 6A is a cross-sectional view showing the cross-sectional shape (180° opening) of a vertebral body perforation guide according to another embodiment. FIG. 6B is a cross-sectional view showing the cross-sectional shape (120° opening) of a vertebral body perforation guide according to another embodiment. FIG. 6C is a cross-sectional view showing the cross-sectional shape (90° opening) of a vertebral body perforation guide according to another embodiment. FIG. 7 is an explanatory diagram showing selected main steps from the procedure for using the treatment instrument of the present invention. FIG. 8 is an explanatory diagram showing an example in which treatment is completed by adding a step of implanting an artificial intervertebral disc before or after the step shown in FIG. 7. FIG. 9 is an explanatory diagram showing an example in which treatment is completed by adding a step of implanting an artificial intervertebral disc before or after the step shown in FIG. 7 and further adding the steps shown in FIGS. 10 to 12. FIG. 10 is an explanatory diagram showing an example of a step that can be added after the step shown in FIG. 7. FIG. 11 is an explanatory diagram showing an example of a step that can be further added after the step shown in FIG. 10. FIG. 12 is an explanatory diagram showing an example in which treatment is completed by adding a final step after the step shown in FIG. 10. FIG. 13A is a reference diagram for explaining the solution principle of the present invention. FIG. 13B is a reference diagram for explaining the solution principle of embodiment 2 of the present invention. FIG. 14 is an explanatory diagram schematically showing an example of the configuration of a vertebral body perforation guide according to a fifth embodiment. FIG. 15 is an explanatory diagram schematically showing a specific example of the configuration of a vertebral body perforation guide according to the fifth embodiment. 16A and 16B are explanatory views schematically showing another specific configuration example of the vertebral body perforation guide according to the fifth embodiment.Fig. 17A is an explanatory view schematically showing a first configuration example of a bone cement filling tube according to the sixth embodiment. Fig. 17B is an explanatory view schematically showing a second configuration example of a bone cement filling tube according to the sixth embodiment. Fig. 17C is an explanatory view schematically showing a third configuration example of a bone cement filling tube according to the sixth embodiment. Fig. 18A is an explanatory view schematically showing one specific configuration example of a vertebral body perforation guide according to the seventh embodiment. Fig. 18B is an explanatory view schematically showing another specific configuration example of a vertebral body perforation guide according to the seventh embodiment.

[0024] 1. Solution Principle of the Present Invention Figure 13A is a reference diagram for explaining the solution principle of the present invention. The solution principle of the present invention will be described with reference to Figures 1, 2, and 7. As described above, an object of the present invention is to provide a safe treatment instrument that can accurately drill every corner of the inside of a vertebral body at the intended location while minimizing skin incisions. To minimize skin incisions, it is optimal to use a linear path of insertion from the pedicle into the vertebral body. However, even if a linear approach is made to the vertebral body via the pedicle, the linear approach is in the direction of reaching the ventral lateral wall of the vertebral body, making it anatomically difficult to guide a linear instrument along that path to the lower endplate of the vertebral body. Therefore, instruments introduced into the vertebral body must be flexible enough to bend within the vertebral body, as described in Patent Document 1, or must have a pre-bent shape, as described in Patent Document 2. However, as described above, flexible or pre-bent instruments have been pointed out as being difficult to remove. Furthermore, with a pre-bent instrument, as shown in Figure 38b of Patent Document 2, the insertion direction of the insertion guide and the extension direction of the instrument on the operator's side open at a large angle, making it impossible to minimize the incision of the skin.

[0025] When inserting a rigid, curved guide through the pedicle and guiding it to the lower endplate region of a vertebral body, it is necessary to begin insertion as close to the center of the pedicle as possible and guide the guide to the vertebral body without perforating the pedicle wall. Perforating the cranial or caudal side of the pedicle risks nerve root damage, while perforating the medial side risks spinal nerve damage. These anatomical characteristics limit the safe transpedicular insertion range of a curved guide compared to inserting a straight guide. Due to the anatomical structure of the pedicle, a straight, cylindrical vertebral body drilling guide structure is easier to insert into the anterior vertebral body structure than a curved guide. Inserting a straight guide also makes it easier to determine the skin incision site. Specifically, the skin incision site can be easily determined by first inserting a syringe needle along the pedicle line, which will be the insertion route, and confirming this with an X-ray. However, in the case of curved structures, the path through the pedicle to lead to the vertebral body is limited, and there are no pre-curved, general-purpose injection needles available for skin incision. Therefore, it is extremely difficult to identify the location of the skin incision for inserting a curved structure. In fact, if a curved structure is inserted along the same trajectory as a straight structure, the direction of the tip structure differs from the direction of the insertion trajectory, making it difficult to insert the curved structure into every corner of the vertebral body along a straight trajectory. In other words, even if a curved structure is forcibly inserted along a straight trajectory, the insertion trajectory will deviate from the direction of the tip structure, making it difficult to insert the curved structure along a straight trajectory. To insert a curved structure into the desired location, the tip must be guided according to the degree of curvature, a technique that requires skill.

[0026] Therefore, the present invention addresses these two issues simultaneously by combining a linear vertebral body drilling guide 1 with a smoothly curved bone drilling instrument 2. As shown in Fig. 13A, the bone drilling instrument 2 is designed to be gradually curved as it approaches the tip (proximal end). Here, "smoothly curved" and "gradually curved" mean that the curvature changes continuously without abrupt changes in the bending angle. If there is a point where the bending angle or curvature changes abruptly, it is expected that the point will get caught on the end of the vertebral body drilling guide, etc., making removal difficult. Therefore, the bone drilling instrument is designed to be smoothly curved.

[0027] On the other hand, after the vertebral body has been excavated, the vertebral body drilling guide 1 can pass other treatment instruments that have a curved structure similar to that of the bone drilling instrument 2, as well as treatment instruments that have a small curve or are straight. Therefore, the surgeon can use the vertebral body drilling guide 1 to introduce treatment instruments such as drilling instruments with notches, protrusions, or irregularities on the tip, Kerrison punches, and balloon catheters into the vertebral body.

[0028] As shown in Fig. 1, the vertebral body drilling guide 1 is a straight cylinder, but its distal and proximal ends are spatula-shaped (first spatula portion 12-1 and second spatula portion 12-2), opening downward and upward, respectively (first opening 11-1 and second opening 11-2). The length L2 of the second spatula portion 12-2 is preferably optimized to extend from the distal end (proximal end) of the pedicle bone hole to a position that slightly protrudes from the patient's body surface (skin). As will be described later and as shown in Fig. 2, the vertebral body drilling guide 1 may further include a third spatula portion 12-3.

[0029] The present invention begins with placing the vertebral body drilling guide 1, which is integrated with the straight cylindrical inner needle 4, inside the pedicle 91 (see also Figure 7 [1]). This is a safe method with an established procedure. After the inner needle 4 is removed, the first spatula portion 12-1 and a part of the second spatula portion 12-2 of the vertebral body drilling guide 1 remain in the vertebral body 90-1 and pedicle 91-1. The second spatula portion 12-2 remaining in the pedicle 91-1 also serves to protect the pedicle 91-1 from being accidentally perforated by the bone drilling instrument 2 that will pass through later. After removing the inner cylindrical needle 4 and placing the vertebral body perforation guide 1, first insert the tip of the bone drilling instrument 2 from point A, which is the base side (stump) of the second spatula portion 12-2, and while keeping the body of the bone drilling instrument 2 in contact with point A, slide the tip in close contact with the bottom of the second spatula portion 12-2 to point B, which is the base side of the first opening 11-1. By contacting the curved portion (concave side, curved inner side) of the bone drilling instrument 2 with the base side (stump) of the second spatula portion 12-2 in this way, the middle part of the bone drilling instrument 2 also contacts the base side (stump) of the second spatula portion 12-2 and serves as a fulcrum, and the tip of the bone drilling instrument 2 contacts the second spatula portion 12-2 and serves as a fulcrum, so that it contacts the vertebral body perforation guide 1 at two points. This allows the bone drilling instrument 2 to be stably supported by the vertebral body drilling guide 1. When the bone drilling instrument 2 is further advanced proximally, the curved tip of the bone drilling instrument 2 protrudes from the first opening 11-1. This protrusion is controlled not by the first opening 11-1 itself, but by the tip of the second opening 11-2 (the proximal end of the first spatula portion 12-1). In other words, when the curved bone drilling instrument 2 comes into contact with the tip of the second opening 11-2 (the proximal end of the first spatula portion 12-1), this serves as a fulcrum, controlling the direction during insertion, and the bone drilling instrument 2 automatically protrudes from the first opening 11-1.

[0030] Furthermore, in the present invention, if the length L2 of the second spatula portion 12-2 is set to a predetermined distance from the pedicle to the skin (by preparing variations according to the size of the patient or by making the length of the second spatula portion 12-2 variable as described below), the trajectory of the bone drilling instrument 2 inserted from the vertebral body drilling guide 1 as it passes through the skin incision 98 can be made to match the trajectory when the vertebral body drilling guide 1 is inserted, and the bone drilling instrument 2 can be passed through with a skin incision of the minimum size (Ws). In other words, if the length L2 of the second spatula portion 12-2 is too long, when the tip of the bone drilling instrument 2 is slid along the second spatula portion 12-2 and the curved portion (concave side) of the bone drilling instrument 2 is inserted while contacting the stump of the second spatula portion 12-2, the distance between the curved portion of the bone drilling instrument 2 and the second spatula portion 12-2 at the skin incision will be large, making it difficult to pass the curved bone drilling instrument 2 through just the minimum skin incision required to insert the vertebral body drilling guide 1.

[0031] The same applies to the bone hole portion of the pedicle 91. That is, by adjusting the distance Ld between the base end of the first spatula portion 12-1 and the end of the second spatula portion 12-2, it is possible to prevent the hole (bone hole) from becoming unintentionally large when the curved bone drilling instrument is inserted into the vertebra. By appropriately setting the distance Ld between the base end of the first spatula portion 12-1 and the end of the second spatula portion 12-2, the size of the bone hole can be made approximately the same as the size of the bone hole formed to insert the vertebral body drilling guide 1, which is a linear guide, so that the curved bone drilling instrument 2 can pass through. On the other hand, if the distance Ld is too short, the position and area reached by the tip of the bone drilling instrument 2 may be limited.

[0032] One key feature of the present invention is that the area where the second opening 11-2 is located is muscle in a living body. Muscle is a very soft tissue. When the curved bone drilling instrument 2 is inserted, the distance between the curved portion of the bone drilling instrument 2 and the second spatula portion 12-2 is greatest at approximately the center of the second opening 11-2 located within the muscle. However, since the bone drilling instrument 2 is located within soft tissue such as muscle, insertion is possible without any problems. As described above, taking into account the large distance at certain locations, it is possible to increase the diameter of the vertebral body drilling guide by forming a thick hollow structure without forming an opening at that location. However, this would require a large skin incision to insert the thick vertebral body drilling guide. By providing the second opening 11-2 as in the present invention, it is not necessary to form a thick central structure to allow the curved bone drilling instrument 2 to pass through the vertebral body drilling guide 1.

[0033] Another important point of the present invention is that the vertebral body drilling guide 1 having openings makes it possible to guide the rigid, curved, rod-shaped bone drilling instrument 2, which has no flexibility, to the intended location by the surgeon, while remaining limited within an anatomical safety zone. When the bone drilling instrument 2 passes through the vertebral body drilling guide 1, the ends of each opening and the tip of the bone drilling instrument 2 function as fulcrums, allowing the bone drilling instrument 2 to be inserted while being integrated and stabilized with the vertebral body drilling guide 1. After the tip of the bone drilling instrument 2 protrudes into the vertebral body from the first opening 11-1, the depth to which the vertebral body drilling guide 1 is inserted and the magnitude (degree of curvature) of the curvature of the bone drilling instrument 2 can be used to determine the position at which the vertebral body is excavated and the position at which the vertebral end plate is drilled, at the point where the vertebral end plate intersects with a perpendicular line drawn vertically downward from the tip of the vertebral body drilling guide. Therefore, the range that the tip of the bone drilling instrument 2 can reach and drill bone can be designed to be limited to the range Wb sandwiched between the distance Wp from the ventral end of the vertebral body and the distance Wd from the dorsal side, thereby limiting it to an anatomically safe area. Furthermore, the surgeon can guide the bone drilling instrument 2 to the intended area by adjusting the depth to which the vertebral body drilling guide 1 is inserted. Another excellent feature of the present invention is that by preparing treatment instruments such as excavation instruments or balloon catheters with different curvatures in advance while leaving one linear vertebral body drilling guide 1 in place, the treatment instruments can be introduced to the intended position of the vertebral body.

[0034] As described above, the present invention enables a non-flexible, curved bone drilling instrument with minimal risk of removal difficulty to be accurately guided into the vertebral body in the region of the lower end plate of a vertebra with minimal skin incision and minimal bone hole, thereby safely drilling and perforating the lower end plate of a vertebra. Furthermore, by using the vertebral drilling guide of the present invention, the tip of a curved bone cement filling tube can be guided along the same trajectory into the cavity drilled with the bone drilling instrument, enabling pinpoint filling of the required amount of bone cement into the excavated cavity. Even without using a vertebral drilling guide, it is possible to introduce a bone cement filling tube after drilling a vertebral body with a bone drilling instrument, but it is difficult to ensure that it follows the same trajectory. It should be emphasized that the use of a vertebral drilling guide enables introduction along the same trajectory. Furthermore, by changing the orientation of the guide so that the opening faces not only the lower end plate but also the upper end plate, drilling can be performed not only toward the lower end plate but also toward the upper end plate and in both left and right directions.

[0035] 2. Overview of the Embodiments First, an overview of the representative embodiments disclosed in the present application will be described. Reference numerals in parentheses in the drawings used in the overview of the representative embodiments merely illustrate components included in the concept of the components to which the reference numerals are attached.

[0036] [1] A bone drilling instrument (Fig. 1) that is guided to the end plate through arc-shaped opening grooves (spatula parts) formed on the top and bottom of a cylindrical vertebral body drilling guide. A representative embodiment disclosed in this application is a treatment instrument (100) that includes a vertebral body drilling guide (1) and a bone drilling instrument (2), and is configured as follows.

[0037] The vertebral body drilling guide has a hollow cylindrical shape along a central axis (x-axis), and includes a first spatula portion (12-1) that opens in a direction perpendicular to the central axis (-z direction) at the tip side along the central axis, and a second spatula portion (12-2) that opens in a direction opposite to the perpendicular direction (z direction) at the base side along the central axis. Note that the cylindrical shape here refers to a cylindrical shape with any cross-sectional shape such as a perfect circle, oval, or ellipse, and a hollow cavity along the central axis.

[0038] The bone drilling instrument is rod-shaped and smoothly curves in the vertical direction along its central axis, and when inserted into the vertebral body drilling guide along the central axis from the distal end of the second spatula portion of the vertebral body drilling guide, its tip portion protrudes from the opening of the first spatula portion.

[0039] This makes it possible to provide a safe treatment instrument that can accurately drill every corner of the inside of a vertebral body at the intended location while minimizing skin incisions in percutaneous vertebral body formation for fractures or in surgery to preventively reinforce a vertebral body with bone cement.

[0040] [2] Vertebral body drilling guide with spatula portions at three locations (Fig. 2) In the treatment instrument of [1], the vertebral body drilling guide further has a third spatula portion (12-3) that is located closer to the base than the second spatula portion and opens in the same direction as the perpendicular direction. The bone drilling tool is inserted into the vertebral body drilling guide from the third spatula portion along the central axis, and when it passes through the second spatula portion along the central axis, the bone drilling tool protrudes from the opening of the first spatula portion.

[0041] This allows the bone drilling instrument (2) to be more stably supported when passing through the vertebral body drilling guide (1).

[0042] [3] Variable-length second spatula portion (Figs. 14-16) In the treatment instrument of [1] or [2], the vertebral body perforation guide has a mechanism that allows the length (L2) of the second spatula portion to be changed.

[0043] This allows the length to be adjusted to suit the patient.

[0044] [4] Length adjustment using a sliding mechanism (Figs. 15-16) In the treatment instrument of [3], the vertebral body drilling guide has a proximal guide (15) including the proximal sides of the first spatula portion and the second spatula portion, and a distal guide (16) including the distal side of the second spatula portion. The inner wall of the proximal guide has a groove (17) or slit (19) along a plane that is parallel to the opening surfaces of the first and second spatula portions and passes through the central axis. The outer wall of the distal guide has a protrusion (18) along a plane that is parallel to the opening surface of the second spatula portion and passes through the central axis. The protrusion on the outer wall of the distal guide can be fitted into the groove or slit on the inner wall of the proximal guide, allowing the proximal guide and the distal guide to be combined and slidable relative to each other along the central axis.

[0045] This allows for easy adjustment of the length (L2) of the second spatula portion (12-2) of the vertebral body drilling guide (1).

[0046] [5] Support portion of bone drilling instrument (Figs. 18A, 18B) In the treatment instrument of [2], the vertebral body drilling guide has a support portion (140) at the distal end of the third spatula portion that extends in the same direction as the vertical direction, and the support portion has an opening (141) through which the bone drilling instrument can pass when inserted from the third spatula portion.

[0047] As a result, when the bone drilling instrument (2) is introduced into the vertebral body, it is guided through three locations: this opening (141), the opening of the third spatula part (12-3), and the opening of the second spatula part (12-2), and is guided to the first spatula part (12-1) on the proximal end side, so that it is stably supported. Furthermore, by appropriately designing the position and size of the opening (141), it is possible to prevent the tip of the bone drilling instrument (2) from accidentally moving to an unexpected position.

[0048] [6] Stopper on vertebral body drilling guide (Fig. 4) In the treatment instrument according to any one of [1] to [5], the vertebral body drilling guide has a stopper (13) on a part of its outer periphery.

[0049] This allows the stopper (13) to come into contact with the vertebral arch at the insertion portion when the vertebral body drilling guide (1) is inserted from the pedicle into the vertebral body, preventing it from being inserted deeper than necessary.

[0050] [7] The cross section of the vertebral body perforation guide is circular (Fig. 5A). In the treatment instrument of any one of [1] to [6], the cross section of the hollow vertebral body perforation guide perpendicular to the central axis is circular.

[0051] This allows the bone hole to be formed in the pedicle to pass the vertebral body drilling guide (1) through to be kept to a minimum.

[0052] [8] The cross section of the vertebral body perforation guide is an ellipse (Figs. 5B and 5C). In the treatment instrument of any one of [1] to [6], the cross section of the hollow vertebral body perforation guide perpendicular to the central axis has a diameter in the perpendicular direction longer than the diameter in the horizontal direction.

[0053] This allows the bone drilling instrument (2) to be more stably supported when passing through the vertebral body drilling guide (1), and allows the area in which vertebral body drilling and drilling can be expanded and adjusted.

[0054] [9] Bone cement filling tube (Figs. 1 and 2) The treatment instrument of any one of [1] to [8] further includes a bone cement filling tube (3). The bone cement filling tube is hollow and tubular along a central axis, curved in the perpendicular direction along the central axis on the proximal side, and has an injection port (31) at its tip. When the bone cement filling tube is inserted into the vertebral body drilling guide along the central axis from the opening (11-2 or 11-3) in the spatula part at the base end of the vertebral body drilling guide, the injection port protrudes from the opening (11-1) in the first spatula part.

[0055] This allows the bone cement filling tube (3) to be introduced into the cavity of the vertebral body excavated by the bone drilling instrument (2) along the same trajectory as the bone drilling instrument (2), making it possible to fill the required amount of bone cement at the intended location within the cavity with pinpoint precision.

[0056]

[10] Side hole in bone cement filling tube (Figs. 17A to 17C) In the treatment instrument of [9], the bone cement filling tube further has an injection port (37) on the outer side of the curved portion on the proximal side.

[0057] This makes it possible to fill cement into each space drilled into the vertebral body using a plurality of bone drilling instruments with different curvatures from a single bone cement filling tube.

[0058]

[11] Inner cylindrical needle (Figs. 1 to 3) The treatment instrument according to any one of [1] to

[10] further includes an inner cylindrical needle (4) that can be inserted into the vertebral body perforation guide.

[0059] This facilitates cooperation with other medical devices that are inserted into the vertebral body through the pedicle.

[0060]

[12] Inner cylindrical needle connectable to vertebral body drilling guide (Fig. 3) In the treatment instrument of

[11] , the inner cylindrical needle has a structure (45) that can be inserted into the vertebral body drilling guide and can be connected to the vertebral body drilling guide at its base. The connecting portion (14) of the vertebral body drilling guide may further have a support portion (140) having an opening (141) through which the bone drilling instrument defined in [5] can pass when inserted from the third spatula portion.

[0061] As a result, as in [5], when the bone drilling instrument (2) is introduced into the vertebral body, it is guided through three locations: this opening (141), the opening of the third spatula part (12-3), and the opening of the second spatula part (12-2), and is guided to the first spatula part (12-1) on the proximal end side, so that it is stably supported. Furthermore, by appropriately designing the position and size of the opening (141), it is possible to prevent the tip of the bone drilling instrument (2) from accidentally moving to an unexpected position.

[0062]

[13] Guide Pin (Figs. 1 to 3) The treatment instrument of

[11] or

[12] further includes a guide pin (5). The inner cylindrical needle (4) has a hollow structure that allows the guide pin to pass through.

[0063] This facilitates cooperation with other medical devices that are inserted into the vertebral body through the pedicle. For example, after inserting and placing a guide pin using another linear bone drilling instrument, the linear bone drilling instrument can be removed, and the vertebral body drilling guide (1) including the inner needle (4) can be safely inserted into the remaining guide pin.

[0064] 3. Details of the embodiment The embodiment will be described in further detail.

[0065] 1 is an explanatory perspective view showing an example of the configuration of a treatment instrument 100 according to a first embodiment. The treatment instrument 100 includes a vertebral body drilling guide 1 and a bone drilling instrument 2, and may further include a bone cement filling tube 3 and an inner cylindrical needle 4.

[0066] The vertebral body drilling guide 1 is a hollow, linear cylinder along a central axis (x-axis), and has a first spatula part 12-1 having a first opening 11-1 that opens at the tip side along the central axis in a direction perpendicular to the central axis (-z direction), and a second spatula part 12-2 having a second opening 11-2 that opens at the base side in the opposite direction to the perpendicular direction (+z direction).

[0067] The bone drilling tool 2 is rod-shaped and curves in the perpendicular direction (-z direction) along its central axis. When inserted into the vertebral body drilling guide 1 from the second opening 11-2 along its central axis through the second opening 11-2, the tip of the tool protrudes from the first opening 11-1. The tip of the bone drilling tool 2 is illustrated in FIG. 1 as a sharp structure 21, but the shape of the tip can be any shape depending on the condition of the bone to be drilled. For example, the tip may be a cylindrical shape with a cut-off edge or a hemispherical shape with smoothly rounded corners. Furthermore, the tip may have a shape that includes notches or irregularities as long as it does not interfere with the bone drilling guide 1.

[0068] FIG. 4 is an explanatory diagram showing a schematic configuration example of a vertebral body drilling guide 1 according to a fourth embodiment, and will be referred to for convenience in the detailed description. The vertebral body drilling guide 1 is inserted into the pedicle 91 until its tip protrudes inside the vertebral body 90. Next, the curved bone drilling instrument 2 is introduced into the vertebral body 90 along the second opening 11-2 while keeping the body of the curved bone drilling instrument 2 in contact with the end of the distal second spatula portion 12-2 of the vertebral body drilling guide 1. The bone drilling instrument 2 then protrudes from the proximal opening 11-1 of the vertebral body drilling guide 1, and its tip (e.g., sharp structure 21) reaches the lower end plate 92b. In this state, the bone drilling instrument 2 can be operated to perforate the end plate 92b and form a drill hole. In other words, the curvature of the bone drilling tool 2 is designed so that when the bone drilling tool 2 is introduced into the vertebral body 90 along the second opening 11-2, which is the opening of the second spatula part 12-2, while being kept in contact with the end of the second spatula part 12-2 on the proximal (distal) side of the vertebral body drilling guide 1 inserted into the pedicle 91, the bone drilling tool 2 protrudes from the opening 11-1 into the vertebral body 90 and its tip (for example, the sharp structure 21) reaches the end plate 92. After forming a perforation in the end plate 92b, when bone cement is injected into the vertebral body 90, the injected bone cement flows out of the end plate 92b through the formed perforation. It is expected that the resin will seep into the intervertebral space adjacent to the vertebrae, and can be used, for example, to reinforce the vertebral body 90, particularly the end plate 92b, in surgery to implant an artificial intervertebral disc. Note that while the vertebral body drilling guide 1 is straight, the bone drilling instrument 2 is curved, and therefore cannot pass directly through the hollow interior of the vertebral body drilling guide 1 and protrudes in the direction of the curve, so openings 11-1, 11-2, and 11-3 (11-3 will be described later in embodiment 2) are provided at appropriate locations in the vertebral body drilling guide 1. For further details, please also refer to "1. Solution principle of the present invention" above.

[0069] The cross-sectional shape of the vertebral body drilling guide 1 may be circular, oval, or elliptical. (However, the cross-sectional shapes of the second spatula portion 12-2 and the third spatula portion 12-3 may be rectangular, hexagonal, or the like.) In other words, the cross-sectional shape of the vertebral body drilling guide 1 in a plane (y-z plane) perpendicular to the hollow central axis (x-axis) may be an oval or ellipse with a flat surface in the center, perpendicular to the central axis, and with a longer diameter in the direction in which the bone drilling instrument 2 curves (z-axis direction), or a perfect circle. Since it is sufficient to allow the bone drilling instrument 2, which curves in the z-axis direction, to pass through, it does not need to be a mathematically strict perfect circle or ellipse; it will suffice as long as it is a figure with a smooth closed curve that can be roughly called an oval, ellipse, or circle.

[0070] 5A to 5C are cross-sectional views showing examples of the cross-sectional shape of the vertebral body perforation guide 1. Fig. 5A shows a perfect circle, Fig. 5B shows an oval with a flat surface in the center, and Fig. 5C shows an ellipse in the cross-sectional shape of the vertebral body perforation guide 1, and the left side shows the cross-sectional shape of the first spatula part 12-1 (first opening 11-1) that opens downward (-z direction), and the right side shows the cross-sectional shape of the second spatula part 12-2 (second opening 11-2) that opens upward (+z direction).

[0071] The vertebral body drilling guide 1 illustrated in FIG. 5A has a cross-sectional shape of a perfect circle with a diameter dz in the z-axis direction and a diameter dy in the y-axis direction equal to each other. The first spatula portion 12-1 has an opening (first opening 11-1) with a width w1 in the -z direction, and the second spatula portion 12-2 has an opening (second opening 11-2) with the same width w1 in the +z direction. It is also possible to combine the first spatula portion 12-1 with a perfect circle and the second spatula portion 12-2 with an ellipse in cross section. The width w1 is equal to the diameter of the bone drilling tool 2 or is wider with a slight margin. The term "perfect circle" does not necessarily mean a perfect circle with strict mathematical accuracy. In practice, it is sufficient for the diameter dz and the diameter dy to be equal to the extent that there is no need to distinguish between the major and minor axes.

[0072] The vertebral body drilling guide 1 illustrated in Figures 5B and 5C has an oval or elliptical cross-sectional shape in which the diameter dz in the z-axis direction, along which the bone drilling instrument 2 curves, is longer than the diameter dy in the y-axis direction. The oval illustrated in Figure 5B is an oval with a flat portion in the center near the y-axis. The curved portion may be semicircular or semi-elliptical, as illustrated in Figure 5B. The shape illustrated in Figure 5C is an ellipse. The width of the openings of the first spatula portion 12-1 and the second spatula portion 12-2 is the same as in Figure 5A, with the width w1. The cross-sectional shapes of the first spatula portion 12-1 and the second spatula portion 12-2 can also be said to be the shapes of the first opening 11-1 and the second opening 11-2. When the bone drilling instrument 2 is passed along the groove of the spatula, the oval or elliptical shape illustrated in Figures 5B and 5C has a deeper groove, allowing the bone drilling instrument 2 to pass stably and less likely to come off the groove. Furthermore, it is advantageous for the surgeon who grasps and operates the vertebral body drilling guide 1 in that the surgeon can sense the direction of curvature of the bone drilling instrument 2 by touch. On the other hand, if the cross-sectional shape of the vertebral body drilling guide 1 is a perfect circle as shown in Fig. 5A, the size of the bone hole formed in the pedicle 91 can be made smaller. This is because the shape of the bone hole that can be formed in the pedicle 91 is close to a perfect circle because it is formed with a drill or an awl, and a perfect circle results in less waste than an oval or elliptical cross-section.

[0073] 6A to 6C are cross-sectional views showing examples of the cross-sectional shape of the opening 11 of the vertebral body drilling guide 1. FIGS. 6A, 6B, and 6C show examples of a 180-degree opening, a 120-degree opening, and a 90-degree opening, respectively. The width of the opening must be at least wide enough to allow the bone drilling instrument 2 to pass through. For example, in the 90-degree opening example of FIG. 6C, the thickness of the bone drilling instrument 2 is thinner than in the other two examples. The size of the opening is appropriately designed by taking into consideration the balance between the ease of passage and the ease of removal of the bone drilling instrument 2.

[0074] [Bone Cement Filling Tube] The treatment instrument 100 more preferably further includes a bone cement filling tube 3. The bone cement filling tube 3 is hollow and cylindrical along its central axis, curved in the perpendicular direction (-z direction) along the central axis, i.e., in the same direction as the bone drilling instrument 2, and has an injection port 31 at its tip. The curvature of the bone cement filling tube 3 is similar to or smaller than that of the bone drilling instrument 2. That is, when the bone cement filling tube 3 is brought into contact with the base end of the vertebral body drilling guide 1 and inserted along the second spatula part 12-2, the injection port 31 protrudes from the first opening 11-1. In other words, the curvature of the bone cement filling tube 3 is designed in this way (so that when the bone cement filling tube 3 is brought into contact with the base end of the vertebral body drilling guide 1 and inserted along the second spatula part 12-2, the injection port 31 protrudes from the first opening 11-1).

[0075] This allows the tip (injection port 31) of the bone cement filling tube 3 to be guided pinpoint and along the same trajectory into the cavity excavated by the bone drilling tool 2, allowing the required amount of bone cement to be filled into the excavated cavity with pinpoint precision.

[0076] [Inner Needle] It is more preferable that the treatment instrument 100 further includes an inner needle 4. The inner needle 4 is a straight cylinder along the central axis (x-axis) and can linearly penetrate the hollow 10 of the vertebral body drilling guide 1. In other words, it does not need to pass through the openings 11-1, 11-2, and 11-3 of the vertebral body drilling guide 1, and can be introduced into the vertebral body simply by passing along the central axis. The tip of the inner needle 4 is provided with a sharp structure 41 that tapers toward the tip, and the outer periphery of the inner needle 4 may be formed with a screw thread (not shown) to assist in tapping.

[0077] [Method of Using the Treatment Instrument] Figure 7 is an explanatory diagram showing selected major steps of the procedure for using the treatment instrument 100 of the present invention. Figure 7 is a side view of two vertebral bodies 90-1 and 90-2, viewed from the side, with the patient's back on the right, the ventral side on the left, the cranial side on the top, and the caudal side on the bottom, with skin 99 shown on the right. The major steps shown are step [1] of inserting the vertebral body drilling guide 1 into the pedicle 91, step [2] of drilling a hole by drilling the lower end plate 92-1b of the vertebral body 90-1 with the bone drilling instrument 2, and step [3] of injecting bone cement 70 into the vertebral body 90-1 near the drilled hole using the bone cement filling tube 3.

[0078] Prior to step [1], the skin 99 is incised and retracted, and a bone hole is formed that penetrates the pedicle 91-1 and reaches the vertebral body 90-1. In step [1], the inner cylindrical needle 4 is inserted into the vertebral body drilling guide 1. While viewing an intraoperative fluoroscopic image on an X-ray, the vertebral body drilling guide 1 and the inner cylindrical needle 4 are inserted into the pre-formed bone hole in the pedicle 91-1, and the tip of the vertebral body drilling guide is introduced into the vertebral body 90-1. Alternatively, without forming a bone hole in advance, the combined inner cylindrical needle and vertebral body drilling guide may be introduced into the vertebral body while viewing an intraoperative fluoroscopic image. Alternatively, a separate, hollow, linear drilling instrument may be introduced into the vertebral body 90-1 through the pedicle 91-1, and a guide pin may be placed in the bone hole in the pedicle 91-1 using the linear drilling instrument. The vertebral body drilling guide 1 and the inner cylindrical needle 4 may then be inserted using the placed guide pin as a guide, and the tip of the vertebral body drilling guide 1 and the inner cylindrical needle 4 may be introduced into the vertebral body 90-1. Alternatively, the guide pin may be inserted directly first, and then the vertebral body drilling guide 1 and the inner cylindrical needle 4, which are integrated into the guide, may be introduced. Alternatively, the inner cylindrical needle 4 of the vertebral body drilling instrument may be first directly introduced into the vertebral body 90-1, and then the vertebral body drilling guide 1 may be introduced into the vertebral body 90-1 using the inner cylindrical needle 4 as a guide. The inner cylindrical needle 4 and the guide pin are then removed. This is an established safe surgical technique.

[0079] In step [2], the bone drilling tool 2 is inserted into the vertebral drilling guide 1 while keeping the main body of the bone drilling tool 2 in contact with the distal end of the second spatula part 12-2 and sliding the tip of the tool against the bottom of the second spatula part 12-2.

[0080] At this time, by optimizing the length of the second spatula part 12-2 so that the distal end of the second spatula part 12-2 can be as close as possible to the retraction part 98, the size of the incision at the retraction part 98 can be minimized. The bone drilling tool 2 is introduced into the vertebral body 90-1 through the opening 11-1 of the proximal first spatula part 12-1 through the hollow part of the vertebral body drilling guide 1. At this time, the tip of the bone drilling tool 2 slides against the bottom of the second spatula part 12-2 and is inserted, so there is no risk of perforating the pedicle wall. In other words, by optimizing the length of the second spatula part 12-2 to the length from the tip of the pedicle, whose wall needs to be protected, to the retraction part 98, two effects can be achieved: protection of the pedicle wall and minimization of the size of the incision at the retraction part 98.

[0081] The bone drilling instrument 2 is advanced further through the first opening 11-1. Because the bone drilling instrument 2 is curved, it is introduced deeply enough that its tip contacts the lower end plate 92-2b of the vertebral body 90-1. The surgeon manipulates the bone drilling instrument 2 while holding and supporting the distal end of the vertebral body drilling guide 1 at the wound retraction site, thereby perforating the end plate 92-2b and forming a drill hole. At this time, the presence of the first spatula portion 12-1 prevents the curved bone drilling instrument 2 from advancing further in a straight line, protecting the bone drilling instrument 2 from accidentally drilling the ventral wall of the vertebral body, and the downward opening guides the tip of the bone drilling instrument 2 to the lower end plate of the vertebral body. By adjusting the insertion depth of the first spatula portion 12-1, i.e., the position of the distal end where the curved portion of the bone drilling tool 2 abuts, the depth direction (closer to the ventral or dorsal) of the lower end plate of the vertebral body that the tip of the bone drilling tool 2 reaches can be adjusted. In other words, by adjusting the insertion depth of the vertebral body drilling guide 1, the surgeon can determine the position to drill a hole in the lower end plate of the vertebral body. In this step, multiple bone drilling tools with various curvatures can be used sequentially as needed to excavate the interior of the vertebral body and drill the end plate. Furthermore, the bone drilling tool can be partially rotated as needed to form and enlarge a cavity.

[0082] In step [3], instead of the bone drilling instrument 2, the bone cement filling tube 3 is inserted from the distal end side of the second spatula portion 12-2 of the vertebral body drilling guide 1, protruding from the first opening 11-1 and introduced into the vertebral body 90-1. The bone cement filling tube 3 is also inserted by sliding its tip against the bottom of the second spatula portion 12-2 while keeping its body in contact with the distal end of the second spatula portion 12-2. Because the bone cement filling tube 3 is curved like the bone drilling instrument 2, the injection port 31 at the tip is introduced deep into the vertebral body 90-1, and the bone cement 70 is injected near the perforation formed in the lower end plate 92-1b. The surgeon injects the bone cement 70 by manipulating the bone cement filling tube 3. The curvature of the bone cement filling tube 3 does not need to be as great as that of the bone drilling instrument 2. The bone drilling tool 2 must be curved sufficiently to allow its tip to contact the lower end plate 92-1b and drill the bone. The bone cement filling tube 3, however, only needs to be curved enough so that the bone cement injected from the injection port 31 at its tip can reach the perforation formed in the end plate 92-1b. Alternatively, a bone cement filling tube 3 with the same curved structure may be used to fill the intervertebral disc cavity through the drilled hole. This allows the tip of the bone cement filling tube 3 to be guided along the same trajectory to the cavity in the vertebral body drilled with the bone drilling tool 2 and the vicinity of the lower end plate 92-1b, allowing for pinpoint filling of the required amount of bone cement. Alternatively, a vertebral drilling tool with a different curvature can be used to drill the desired area and then fill the required amount of bone cement. Although not shown, it is also possible to pour bone cement from a straight bone cement filling tube into the cavity created by a curved bone drilling tool.

[0083] The method of using the treatment instrument of the present invention, which includes the above steps [1] to [3], can provide a safe method of using the treatment instrument that can accurately excavate the intended location deep inside the vertebral body while minimizing skin incisions in percutaneous vertebral body formation surgery for fractures and surgery to preventively reinforce the vertebral body with bone cement.

[0084] These steps [1] to [3] are the main steps according to the present invention, and necessary steps can be added before, after, or during these steps to complete an appropriate surgical procedure.

[0085] 8 is an explanatory diagram showing an example in which treatment is completed by adding step [A] of implanting an artificial intervertebral disc 9 before or after the step shown in FIG. 7. In step [A], the artificial intervertebral disc 9 is inserted and implanted in the intervertebral space between the cranial vertebral body 90-1 and the caudal vertebral body 90-2. The end plate 92-1b, with which the upper surface of the artificial intervertebral disc 9 contacts, is reinforced with bone cement 70, or the bone cement 70 seeps into the space between the end plate 92-1b and the artificial intervertebral disc 9 through perforations formed in the end plate 92-1b, reinforcing the end plate 92-1b or strengthening the bond with the artificial intervertebral disc 9.

[0086] 9 is an explanatory diagram showing an example in which a step of implanting an artificial intervertebral disc 9 is added before or after the step shown in Fig. 7, and further steps shown in Figs. 10 to 12 are added to complete the treatment. The bone cement 70, which reinforces the end plate 92-1b and, in some cases, contributes to the bonding between the end plate 92-1b and the artificial intervertebral disc 9, is more firmly held within the vertebral body in combination with the bone cement 70-1 injected into the vertebral body in steps [4] to

[10] (Figs. 10 to 12) described below, thereby reducing the risk of complications such as the artificial intervertebral disc 9 settling within the vertebral body or dislocation.

[0087] 10 to 12 are explanatory diagrams showing steps [4] to

[10] , which are examples of steps that can be added as needed, either simultaneously with or after the steps shown in Fig. 7. These steps may be used in conjunction with the step of implanting the artificial intervertebral disc 9 described with reference to Fig. 9, or may be applied to another surgery that does not presuppose the implantation of the artificial intervertebral disc 9. Although not shown in the figures, the drilling guide may also be inverted upside down to create a bone hole in the vertebral body below (caudal side) that sandwiches the artificial intervertebral disc, thereby reinforcing the vertebral end plate 92-2t (the upper end plate of the caudal vertebral body).

[0088] In step [4], the guide pin 5 is introduced into the vertebral body 90-1 from the tip of the first spatula part 12-1, passing through the hollow part from the second spatula part 12-2 on the distal side of the vertebral body drilling guide 1 and the first spatula part 12-1 on the proximal side. Because the guide pin 5 is linear, it does not need to pass through the first and second openings 11-1 and 11-2, and is introduced into the vertebral body 90-1 simply by passing in the direction of the central axis. The thickness of the guide pin 5 may be made thicker to match the inner diameter of the vertebral body drilling guide 1.

[0089] In step [5], the vertebral body perforation guide 1 is removed by sliding it along the inserted guide pin 5.

[0090] In step [6], the driver 7 and screw 6 are introduced so as to cover and follow the guide pin 5. The driver 7 and screw 6 may be, for example, a driver included in the treatment instrument disclosed in Japanese Patent No. 7300133 and a screw that can be screwed with that treatment instrument. The driver 7 has a structure that is fitted into the head of the screw 6 and connected, and the driver 7 and screw 6 each have a through-hole formed therein. The through-holes are connected when the driver 7 and the screw 6 are connected, allowing the guide pin 5 and the bone cement filling tube 8, which will be described later, to pass through. The body of the screw 6, excluding the head, may be formed with threads for tapping the surrounding bone and screwing in, or the threads may be limited to the body near the head, with the proximal side being flat or grooved.

[0091] In step [7], the screw 6 is screwed into the pedicle 91-1 by operating the driver 7. The screw 6 is screwed in until the tip of the screw 6 reaches the inside of the vertebral body 90-1, and the guide pin 5 is then removed. Before screwing in the screw 6, the guide pin 5 may be removed, and instead an inner tube (different from the inner tube needle 4 of the present invention) included in the treatment instrument disclosed in the aforementioned Japanese Patent No. 7300133 may be inserted, and the screw 6 and driver 7 may be screwed in as a single unit.

[0092] In step [8], a straight bone cement filling tube 8 is inserted into the through-hole connected by the driver 7 and the screw 6 until it reaches the vertebral body 90-1, and bone cement 70-1 is injected into the vertebral body 90-1. This bone cement filling tube 8 may be a general-purpose bone cement filling tube, and is linear, unlike the bone cement filling tube 3 used in step [3]. The bone cement 70-1 is injected from the center of the vertebral body 90-1 toward the cranial side of the bone cement 70 injected in step [3]. If the vertebral body 90-1 has a compression fracture, for example, a treatment step may be added before step [8] in which the vertebral body 90-1 is ground and a balloon is inflated using a balloon catheter to restore the collapsed vertebral body 90-1 to a healthy size.

[0093] In step [9], the screw 6 is screwed into the bone cement 70-1 by operating the driver 7. The screw 6 is screwed in before the bone cement 70-1 hardens, and after hardening, it becomes integrated with the bone cement 70-1 and supports the hardened bone cement 70-1 from the pedicle 91-1. The screw 6 may have bone cement injection ports not only at the tip but also on the side, and the screw 6 may be inserted to the final depth first, and then the bone cement may be injected from the side injection port to fill the surrounding area.

[0094] In step

[10] , the driver 7 is removed, the wound opening 98 is sutured, and the surgery is completed.

[0095] As described above, all steps can be performed by operating the instruments from outside the body outside the wound opening 98, so the size of the wound opening 98 can be minimized to about the thickness of the instruments.

[0096] Although not shown, after step [2] shown in FIG. 7, instead of filling the bone cement 70 in step [3], the procedure may proceed to step [4] in FIG. 10, and the bone cement 70 may be filled into the cavity formed in step [2] in FIG. 7 via the through-hole in the central axis of the screw 6, as exemplified in step [8] in FIG. 11.

[0097] 2 is an explanatory perspective view showing an example of the configuration of a treatment instrument according to a second embodiment. The vertebral body perforation guide 1 of the treatment instrument 100 according to the second embodiment has spatula portions and openings at three locations.

[0098] The vertebral body drilling guide 1 further includes a third spatula portion 12-3 that opens closer to the base (distal side, closer to the surgeon) than the second spatula portion 12-2 of the vertebral body drilling guide 1 of embodiment 1. The third spatula portion 12-3 has a third opening 11-3 that opens in the same direction (-z direction) as the first opening 11-1. The bone drilling instrument 2 is inserted into the vertebral body drilling guide 1 from the third opening 11-3 along the central axis, and is inserted deeper along the central axis so that its tip slides while in close contact with the bottom of the second spatula portion 12-2. At this time, the bone drilling instrument 2 passes through, overhanging toward the second opening 11-2 (+z direction), and the tip protrudes from the first opening 11-1. This allows the bone drilling instrument 2 to be supported more stably when inserted into the vertebral body drilling guide 1 than in embodiment 1.

[0099] FIG. 13B is a reference diagram for explaining the solution principle of the second embodiment.

[0100] 13A , if the bone drilling tool 2 is moved upward from the second spatula part 12-2 of the vertebral body drilling guide 1 at the fulcrum A when the incision of the retraction portion 98 is large, there is a risk that the bone drilling tool 2 protruding from the first opening 11-1 will move unintentionally toward the front (distal direction), resulting in perforation of a region close to neural tissue. By providing a third spatula portion 12-3 on the vertebral body drilling guide 1 and inserting the bone drilling instrument 2 through the third opening 11-3 on the opposite side, even if the bone drilling instrument 2 is curved, it can be restricted so that it always passes through fulcrum A, which is the connection point between the third spatula portion 12-3 and the second spatula portion 12-2, in addition to fulcrum B, which is the connection point between the first spatula portion 12-1 and the second spatula portion 12-2.This means that the bone drilling instrument 2 can be stably supported at these two points, fulcrum A and fulcrum B, and the area to be drilled in the bone can be limited to a safe area, preventing the risk of drilling an area unintended by the surgeon.

[0101] The length L2 of the second spatula portion 12-2 may be shorter than that in the first embodiment described above. In the first embodiment, the distal end of the second spatula portion 12-2 (point A in FIG. 13A ) is one of the fulcrums supporting the bone drilling instrument 2 and corresponds to the position where the surgeon holds the vertebral body drilling guide 1, and therefore must be outside the body (outside the skin). Since the distance between the second spatula portion 12-2 and the bone drilling instrument 2 is minimized at this fulcrum, the size of the incision at the wound opening 98 can be minimized by bringing the fulcrum as close to the skin as possible, i.e., by minimizing the length of the second spatula portion 12-2 protruding from the skin. In the second embodiment, on the other hand, the fulcrum where the vertebral body drilling guide 1 supports the bone drilling instrument 2 is the connection point (point A) between the second spatula portion 12-2 and the third spatula portion 12-3. The curving bone drilling instrument 2 always passes through this fulcrum (connection point), and the distance at this fulcrum (connection point) is minimized. However, because the surgeon grasps and operates the third spatula portion 12-3, the fulcrum (connection point) may be located inside the skin (proximal, inside the body). As illustrated in FIG. 13B , when the patient is thin and the skin is close to the spine (as shown by "99 in case P"), the connection point (point A) between the second spatula portion 12-2 and the third spatula portion 12-3 is outside the body, and the surgeon can grasp the third spatula portion 12-3. When the patient is obese or otherwise far from the skin and spine (as shown by "99 in case Q"), even if the connection point (point A) is buried inside the body, the surgeon can still grasp the third spatula portion 12-3, and the surgery can be performed without any problems. Furthermore, even if the connection point (point A) is buried inside the body, the bone drilling instrument 2 can be inserted without significantly changing its trajectory. However, if the connection point (point A) penetrates too deep into the skin, the distance between the vertebral body drilling guide 1 and the bone drilling instrument 2 will become too large distal to point A, which is the fulcrum, and a large incision of the skin will be required, which is undesirable. Therefore, it is preferable that the position of the connection point between the second spatula portion 12-2 and the third spatula portion 12-3 be slightly inside the skin.

[0102] As described above, by providing the third spatula portion 12-3 on the vertebral body drilling guide 1, the reach of the bone drilling instrument 2 can be limited to a safe area while keeping the size of the opening of the wound retraction portion 98 small.

[0103] The treatment instrument 100 of this embodiment 2 may also be configured to include a bone cement filling tube 3 and / or an inner cylindrical needle 4, as in embodiment 1. The method of use and the effects thereof are the same as in embodiment 1, so duplicated explanations will be omitted. In addition, the cross-sectional shape of the vertebral body drilling guide 1 is the same as in embodiment 1 described with reference to Figures 5A to 5C and 6A to 6C, so duplicated explanations will be omitted.

[0104] [Embodiment 3] Figure 3 is an explanatory perspective view showing an example of the configuration of a vertebral body drilling guide 1 and an inner cylindrical needle 4 according to a third embodiment. The inner cylindrical needle 4 is cylindrical and has a hollow structure that allows a guide pin 5 to pass through. It can be inserted into the vertebral body drilling guide 1 and has a connecting portion 45 that can be connected to the connecting portion 14 provided on the vertebral body drilling guide 1 at its base. The connecting portion 14 of the vertebral body drilling guide 1 and the connecting portion 45 of the inner cylindrical needle 4 can be connected using a mating male-female screw structure, a mating latch structure, or any other structure. Furthermore, the connection with the vertebral body drilling guide 1 may be fixed (latched) by passing the guide pin 5 through a through-hole that penetrates the central axis of the inner cylindrical needle 4. Additionally or alternatively, the end where the connecting portions 14 and 45 are provided may be provided with a grip to facilitate operation. This facilitates connection with other medical devices that are inserted into the vertebral body via the pedicle. Although not shown, the inner cylindrical needle 4 may not have a structure for passing a guide pin.

[0105] As will be described in detail in the seventh embodiment below, a support part 140 having an opening 141 for passing the bone drilling instrument 2 may be attached to the connecting part 14 at the distal end of the vertebral body drilling guide 1. As a result, when the bone drilling instrument 2 is introduced into the vertebral body, it is guided to the first spatula part 12-1 on the proximal end side through three places: this opening 141, the opening of the third spatula part 12-3, and the opening of the second spatula part 12-2, and is therefore stably supported. Furthermore, by appropriately designing the position and size of the opening 141, it is possible to prevent the tip of the bone drilling instrument 2 from inadvertently moving to an unexpected position.

[0106] 4 is an explanatory diagram schematically illustrating an example of the configuration of a vertebral body drilling guide according to a fourth embodiment. In the treatment instrument 100 of the above-described embodiments 1 to 3, a stopper 13 is provided on a part of the outer periphery of the vertebral body drilling guide 1. When the vertebral body drilling guide 1 is inserted from the pedicle 91 into the vertebral body 90, the stopper 13 abuts against the vertebral arch of the inserted portion, preventing it from being inserted deeper than necessary.

[0107] [Embodiment 5] Figure 14 is an explanatory diagram schematically illustrating an example of the configuration of a vertebral body drilling guide 1 according to a fifth embodiment. The vertebral body drilling guide 1 has a mechanism that allows the length (L2) of the second spatula portion 12-2 to be changed. This allows the length to be adjusted to suit the patient. Figure 14 illustrates a vertebral body drilling guide 1 that includes not only the first and second spatula portions as shown in Figure 2, but also a third spatula portion, but the third spatula portion is not necessarily provided.

[0108] As explained in "1. Solution Principle of the Present Invention," the length of the second spatula portion 12-2 is very important in the vertebral body drilling guide 1. When the vertebral body drilling guide 1 is inserted into the pedicle, the proximal ends of the first spatula portion 12-1 and the second spatula portion 12-2 serve as fulcrums for redirecting the curved bone drilling instrument 2 from the direction passing through the bone hole in the pedicle to the direction toward the lower end plate, and are important points (positions) that determine the drilling area of ​​the lower end plate. Furthermore, by configuring the distal end of the second spatula portion 12-2 to support the bone drilling instrument 2 at a position as close as possible to the patient's skin (wound wound 98), the size of the incision in the wound wound 98 can be minimized. Therefore, by optimizing the distance from the proximal end to the distal end of the second spatula portion 12-2, i.e., the length L2 of the second spatula portion 12-2, for the patient, it is possible to maximize both the function of limiting the perforation area of ​​the lower end plate to a safe area (safety) and the function of minimizing the size of the incision at the wound opening portion 98 (minimally invasiveness).

[0109] Thus, providing the vertebral body drilling guide 1 with a mechanism that can adjust the length (L2) of the second spatula portion 12-2 is extremely important in order to optimize the length (L2) of the second spatula portion 12-2 for the patient and maximize safety and minimal invasiveness.

[0110] 15 is an explanatory diagram showing a specific example of the configuration of the vertebral body drilling guide 1. The upper side shows an enlarged perspective view of the connecting portion from the side, and the lower side shows cross-sectional views at three locations z1, z2, and z3 shown in the upper side (z1-z1 x-section, z2-z2 x-section, and z3-z3 x-section).

[0111] The vertebral body drilling guide 1 has a proximal guide 15 having the proximal sides of the first spatula portion 12-1 and the second spatula portion 12-2, and a distal guide 16 having the distal side of the second spatula portion 12-2 and the third spatula portion 12-3. The inner wall of the proximal guide 15 has a groove 17 along a plane that is parallel to the opening surfaces of the first and second spatula portions 12-1 and 12-2 and passes through the central axis. The outer wall of the distal guide 16 has a protrusion 18 along a plane that is parallel to the opening surfaces of the second and third spatula portions 12-2 and 12-3 and passes through the central axis. The protrusion 18 on the outer wall of the distal guide 16 fits into the groove 17 on the inner wall of the proximal guide 15, combining the proximal guide 15 and the distal guide 16 and allowing them to slide relative to each other along the central axis, thereby constituting a mechanism for adjusting the length (L2) of the second spatula portion 12-2. Groove 17 is formed from the connection with first spatula part 12-1 through z1-z1 cross section, z2-z2 cross section, and z3-z3 cross section to near the distal end. Protrusion 18 is formed on the outer wall on the tip side (proximal side) of distal guide 16, fits into groove 17 to connect proximal guide 15 and distal guide 16, and slides along groove 17 to adjust the length of second spatula part 12-2.

[0112] Although Figure 15 shows an example in which the groove 17 is open at the proximal end but closed at the distal end, it may also be closed at the proximal end. By closing both ends, the adjustment range of the length (L2) is determined. It also makes it difficult to remove. On the other hand, by leaving one end open, it makes it easier to connect and disconnect the proximal guide 15 and the distal guide 16.

[0113] In the example of Figure 15, the proximal side is on the outside and wraps around the distal side, but the reverse is also possible. However, in the reverse case, it is desirable to devise a way to prevent the proximal end of the distal side from getting caught in the bone hole of the pedicle into which it is inserted, and to prevent bone fragments and other foreign objects from getting caught in the gap.

[0114] 16A and 16B are explanatory diagrams schematically illustrating another specific configuration example of the vertebral body drilling guide 1. As in FIG. 15 , the upper side shows an enlarged perspective view of the connection portion, and the lower side shows cross-sectional views (z1-z1 x-section, z2-z2 x-section, z3-z3 x-section) at three locations z1, z2, and z3 shown in the upper side. Instead of the groove 17 shown in the configuration example of FIG. 15 , a slit 19 is formed in the outer wall of the proximal guide 15 along a plane parallel to the opening surfaces of the first and second spatula portions 12-1 and 12-2 and passing through the central axis. Similar to the configuration example of FIG. 15 , the protrusion 18 of the distal guide 16 fits into and connects to this slit 19 instead of the groove 17 shown in the configuration example of FIG. 15 , and the length (L2) is adjusted by sliding. Furthermore, various other modifications are also similar to the configuration example of FIG. 15 .

[0115] 16A, the protrusion 18 is disposed at the upper end of the second spatula portion 12-2, whereas in the configuration example of Fig. 16B, the protrusion 18 is formed slightly below the upper end of the second spatula portion 12-2, and the upper end of the second spatula portion 12-2 of the proximal guide 15 is aligned with the upper end of the second spatula portion 12-2 of the distal guide 16. In the configuration example of Fig. 16A, the protrusion 18 is formed by partially bending the upper end of the second spatula portion 12-2, which makes manufacturing easy, whereas in the configuration example of Fig. 16B, the second spatula portion 12-2 of the proximal guide 15 and the second spatula portion 12-2 of the distal guide 16 contact each other on both the upper and lower sides of the slit 19, resulting in a stable connection.

[0116] As described above, a mechanism for adjusting the length of the second spatula portion 12-2 of the vertebral body drilling guide 1 can be easily constructed.

[0117] [Embodiment 6] A side hole may be provided on the proximal side of the bone cement filling tube 3. This allows cement to be filled into each space created by drilling a vertebral body with multiple vertebral body drilling instruments with different curvatures from a single bone cement filling tube 3.

[0118] 17A to 17C are explanatory diagrams schematically illustrating exemplary configurations of the bone cement filling tube 3 according to this embodiment. In addition to the injection port 31 at the tip (proximal end), the bone cement filling tube 3 of this embodiment 6 has an injection port 37 on the outer side of the curved portion on the proximal side. While Figures 17A to 17C show an example in which three injection ports 37 are formed on the outer side of the curve (the forward direction of the insertion direction of the vertebral body drilling guide 1), the direction and number of injection ports 37 are optional. The sizes of the holes may be different, and the injection ports 31 and 37 may be connected.

[0119] 17A, bone cement is injected from a syringe or the like connected to the distal end of the bone cement filling tube 3. The syringe of the syringe is filled with bone cement beforehand, and the syringe is pushed by the plunger to deliver the bone cement into the bone cement filling tube 3. By appropriately designing the opening diameters of the injection port 31 and each of the injection ports 37, if there are multiple injection ports, the bone cement can be injected at the desired location.

[0120] The bone cement filling tube 3 shown in Figure 17B consists of an outer tube 34 and a pusher rod 36. Bone cement is pre-filled into the outer tube 34, and after the tip is introduced into the affected vertebral body, the pusher rod 36 pushes the bone cement out through the injection ports 31 and 37 and injects it into the vertebral body. The pusher rod 36 is preferably straight and not curved. Accordingly, the distal portion of the outer tube 34 into which the pusher rod 36 is pushed is also preferably straight and not curved. This is because a straight tube shape reduces costs. Alternatively, the outer tube 34 may be curved as needed, and the pusher rod 36 may be made of a plastic material so that it can bend along the curve. Alternatively, the bone cement filling tube 3 and the pusher rod 36 may have the same curved structure from the base, allowing the pusher rod 36 to penetrate the bone cement filling tube 3 to the tip.

[0121] The bone cement filling tube 3 shown in Figure 17C comprises an outer cylindrical portion 34, an inner cylindrical portion 35, and a pusher rod 36. Bone cement is pre-filled into the inner cylindrical portion 35. After the distal end of the outer cylindrical portion 34 of the bone cement filling tube 3 is introduced into the affected vertebral body, the bone cement is pushed out of the distal end of the outer cylindrical portion 34 by the pusher rod 36, and injected through the injection ports 31 and 37 into the vertebral body. The inner cylindrical portion 35 and the pusher rod 36 are preferably straight and not curved. Similarly, the distal portion of the outer cylindrical portion 34, into which the pusher rod 36 is pushed, is also preferably straight and not curved, as in the example of Figure 17B. The straight and not curved inner cylindrical portion 35 and the pusher rod 36 can be made from general-purpose bone cement filling tubes, which have a proven track record, pose little risk, and are inexpensive. Alternatively, the outer cylindrical portion 34 may be provided with the required curvature, and the inner cylindrical portion 35 and the pusher rod 36 may be made of a plastic material so as to bend along the curvature.

[0122] Seventh Embodiment FIG. 18 is an explanatory view schematically showing a specific configuration example of a vertebral body drilling guide according to a seventh embodiment.

[0123] The vertebral body drilling guide 1, which includes a third spatula portion 12-3 in addition to the first and second spatula portions 12-1 and 12-2 shown in FIG. 2, includes a support portion 140 at the distal end of the third spatula portion 12-1, extending in the same direction (downward) as the openings of the first and third spatula portions 12-1 and 12-3. The support portion 140 has an opening 141 through which the bone drilling tool 2 can pass when inserted from the third spatula portion 12-3. As shown in FIG. 18A, the support portion 140 is plate-shaped and is welded, brazed, or glued to the distal end of the third spatula portion 12-3, or is detachably attached thereto. The opening 141 is formed long in the vertical direction and has a width approximately equal to the diameter of the bone drilling tool 2 plus a small margin.

[0124] As a result, when the bone drilling tool 2 is introduced into the vertebral body, it passes through three locations: the opening 141, the opening of the third spatula part 12-3 (third opening 11-3), and the opening of the second spatula part 12-2 (second opening 11-2), and is guided to the first spatula part 12-1 on the proximal end side, thereby providing stable support. The width and length of the opening 141 are determined taking into consideration the position through which the bone drilling tool 2 passes when inserted into the vertebral body drilling guide 1. In other words, by appropriately designing the position and size of the opening 141, it is possible to prevent the tip of the bone drilling tool 2 from inadvertently moving to an unexpected position. While the opening 141 is shown as a closed curve, it may also be open. Furthermore, the bone drilling tool 2 may be provided with a handle at its base so that it can be inserted by hitting it with a hammer or the like. The handle may come into contact with the support part 140 and function as a stopper to prevent the bone drilling tool from being inserted beyond a certain depth.

[0125] FIG. 18B shows another example configuration of the vertebral body perforation guide 1 of the seventh embodiment. Like the vertebral body perforation guide 1 of the third embodiment illustrated in FIG. 3, the vertebral body perforation guide 1 includes a connecting portion 14 for connecting to the inserted inner cylindrical needle 4. In the seventh embodiment, the connecting portion 14 is formed so that the supporting portion 140 extends in the same direction (downward) as the openings of the first and third spatula portions 12-1 and 12-3. The opening 142 and the opening 141 may be integrated into the same hole. The position and size of the opening 141 formed in the supporting portion 140 are determined in the same manner as in the example of FIG. 18A described above. The supporting portion 140 further includes another opening 142 for passing the inner cylindrical needle 4. This structure is similar to that of the third embodiment. The example configuration illustrated in FIG. 18A does not include an opening 142 for passing the inner cylindrical needle 4, but such an opening may be provided. This allows for the use of not only the inner cylindrical needle 4 but also other instruments, such as an excavation tool, a balloon catheter, or a guide pin.

[0126] 18A and 18B is attached in the direction in which the first and third spatula parts 12-1 and 12-3 open, i.e., in a direction perpendicular to the vertebral body drilling guide 1, but as long as the position and size of the opening are appropriately defined, the method of attaching the support part 140, including the attachment direction, is arbitrary. Also, although the openings 141 illustrated in Figures 18A and 18B are all closed all around, they may be partially open.

[0127] The invention made by the inventor has been specifically described above based on an embodiment, but it goes without saying that the invention is not limited thereto and can be modified in various ways without departing from the spirit of the invention.

[0128] The present invention relates to a spinal treatment instrument for filling a spine with bone cement, and is particularly suitable for use in surgery for stabilizing and reinforcing the spine.

[0129] DESCRIPTION OF SYMBOLS 1 Vertebral body drilling guide 2 Bone drilling instrument 3 Bone cement filling tube 4 Inner cylindrical needle 5 Guide pin 6 Screw 7 Driver 8 Bone cement filling tube 9 Artificial intervertebral disc 10 Hollow 11 Opening 12 Spatula part 13 Stopper 14 Connecting part 140 Support part 141, 142 Opening 15 Proximal guide 16 Distal guide 17 Groove part (concave part) 18 Projection (convex part) 19 Slit 21 Sharp structure 22, 32, 42 Straight part 23, 33 Curved part 30, 40 Hollow 31, 37 Injection port 34 Outer cylindrical part 35 Inner cylindrical part 36 Pushing rod 41 Tip part 45 Connecting part 50 Guide pin 70 Bone cement 90 Vertebral body 91 Pedicle 92, 92t, 92b end plate 98 retraction site 99 skin 100 treatment instrument

Claims

1. A medical treatment instrument comprising a vertebral body drilling guide and a bone drilling instrument, wherein the vertebral body drilling guide is a hollow cylinder along a central axis, and has a first spatula part that opens in a direction perpendicular to the central axis at the tip side along the central axis, and a second spatula part that opens in a direction opposite to the perpendicular direction at the base side along the central axis, and the bone drilling instrument is rod-shaped and smoothly curves in the perpendicular direction along the central axis, and when inserted into the vertebral body drilling guide along the central axis from the distal end of the second spatula part of the vertebral body drilling guide, the tip part protrudes from the opening of the first spatula part.

2. A treatment instrument according to claim 1, wherein the vertebral body drilling guide further has a third spatula portion that opens in the same direction as the perpendicular direction and is located closer to the base than the second spatula portion, and the bone drilling instrument is inserted from the third spatula portion along the central axis into the vertebral body drilling guide, and when it passes through the second spatula portion along the central axis, the bone drilling instrument protrudes from the opening of the first spatula portion.

3. A treatment instrument according to claim 1 or 2, wherein the vertebral body drilling guide has a mechanism that allows the length of the second spatula portion to be changed.

4. A therapeutic instrument according to claim 3, wherein the vertebral body perforation guide comprises a proximal guide having the proximal sides of the first spatula portion and the second spatula portion, and a distal guide including the distal side of the second spatula portion, the inner wall of the proximal guide having a groove or slit along a plane that is parallel to the opening faces of the first and second spatula portions and passes through the central axis, the outer wall of the distal guide having a convex portion along a plane that is parallel to the opening face of the second spatula portion and passes through the central axis, and the convex portion on the outer wall of the distal guide can be fitted into the groove or slit on the inner wall of the proximal guide, allowing the proximal guide and the distal guide to be combined and slidable relative to each other along the central axis.

5. A treatment instrument according to claim 2, wherein the vertebral body drilling guide has a support part at the distal end of the third spatula part that extends in the same direction as the perpendicular direction, and the support part has an opening through which the bone drilling instrument can pass when inserted from the third spatula part.

6. A treatment instrument according to any one of claims 1 to 5, wherein the vertebral body drilling guide has a stopper on a part of its outer periphery.

7. A treatment instrument according to any one of claims 1 to 6, wherein the cross-sectional shape of the hollow vertebral body drilling guide perpendicular to the central axis is circular.

8. A treatment instrument according to any one of claims 1 to 6, wherein the cross-sectional shape of the hollow vertebral body drilling guide perpendicular to the central axis has a diameter in the perpendicular direction longer than a diameter in the horizontal direction.

9. A treatment instrument according to any one of claims 1 to 8, further comprising a bone cement filling tube, which is hollow and cylindrical along a central axis, curved in the perpendicular direction along the central axis on the proximal side, and has an injection port at its tip, and when inserted into the vertebral body drilling guide along the central axis from the opening of the spatula part at the base end of the vertebral body drilling guide, the injection port protrudes from the opening of the first spatula part.

10. A treatment device according to claim 9, wherein the bone cement filling tube further has an outlet in the outward direction of the curved portion on the proximal side.

11. A treatment instrument according to any one of claims 1 to 10, further comprising an inner cylindrical needle that can be inserted into the vertebral body perforation guide.

12. The treatment instrument according to claim 11, wherein the inner cylindrical needle has a structure that allows it to be inserted into the vertebral body perforation guide and can be connected to the vertebral body perforation guide at its base.

13. A treatment instrument according to claim 11 or 12, further comprising a guide pin, and the inner cylindrical needle has a hollow structure that allows the guide pin to pass through.

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