Treatment equipment

Abstract

This treatment instrument comprises a bone cement molding tool and a bone cement fixation tool inserted into an internal fixation tool that internally fixes bone cement filled into a vertebral body while being supported from a pedicle. The treatment instrument is configured as follows. The internal fixation tool has a through-hole in a central axis direction from the head to the tip, and can be inserted into and removed from the bone cement along the central axis thereof. The bone cement molding tool is inserted into the bone cement through the through-hole to mold a hole of a predetermined shape after the internal fixation tool is screwed into the bone cement. The bone cement fixation tool has a tip inserted into the hole molded above, and the tip is inserted into the hole through the through-hole of the internal fixation tool, thereby suppressing the rotation and / or movement in a pull-out direction of the bone cement.

Description

Technical Field

[0005]

[0001] The present invention relates to a treatment instrument for operating a medical cylindrical internal fixation instrument, and in particular, it can be suitably used for internal fixation surgery of a vertebral body which is an affected part.

Background Art

[0002] As treatment methods for spinal compression fractures, vertebroplasty and spinal fixation are known. The spine consists of stacked vertebral bodies and the vertebral arches, pedicles, articular processes, etc. that support them. The vertebral body is a cylindrical bone that sandwiches the nucleus pulposus and the annulus fibrosus surrounding it vertically, and is supported by two left and right pedicles extending from the vertebral arch. The vertebral arches are connected vertically by the upper and lower articular processes and support the vertebral body through the pedicles to form the spine. Compression fracture is a disease in which the vertebral body is crushed and damaged by vertical compression. Vertebroplasty is a surgery to reconstruct the crushed vertebral body, and for example, a surgical method of filling the vertebral body with medical cement is adopted. Spinal fixation is a surgical method of fixing the crushed vertebral body and the healthy vertebral bodies above and below it with an instrument. Screws are screwed into the crushed vertebral body and the healthy vertebral bodies above and below it from the pedicles, and the heads of the screws are connected to rods passed in the vertical direction to each other for fixation. If the symptoms are mild, vertebroplasty is adopted, but if the symptoms are severe, spinal fixation is necessary.

[0003] Various screws used for these treatments have been proposed.

[0004] Patent Document 1 discloses a medical screw provided with a longitudinal through-hole along the central axis and an opening on the side surface communicating with the through-hole. An injection instrument such as a syringe is attached to the head of the screw, and bone cement or a bioactive substance is injected into the surrounding bone through the opening on the side surface from the through-hole, and the surrounding bone is reinforced (

[0053] ~

[0057] , Figs. 6-8).

[0005] Patent Document 2 discloses a medical screw that can be easily removed from a fracture site into which it has been screwed. The medical screw has a hollow section formed from the head to the tip along the central axis, and threads are formed on the side so that it can be screwed into the bone. Near the inner tip of the hollow section of the screw, there is a reverse thread (reverse internal thread section), and it is possible to pull it out by using an extraction tool that has a tip that engages with this reverse internal thread section. More specifically, the extraction tool is inserted from the hollow section, the tip engages with the reverse internal thread section of the screw and integrates with it, and the extraction tool is rotated to pull the screw out of the body. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] US release 2011 / 0040337A1 [Patent Document 2] Japanese Patent Publication No. 2016-209295 [Overview of the project] [Problems that the invention aims to solve]

[0007] The inventors of this invention have identified a problem in the lack of sufficient development of medical instruments and screws suitable for surgical procedures that combine vertebroplasty and pedicle formation as described above.

[0008] The inventor has invented a treatment device to solve this problem and filed an international patent application as PCT / JP2022 / 036147. This invention is a treatment device integrated with a screw having a through hole along its central axis and tappable threads on its sides. The device is configured so that a screwdriver can be attached to the head of the screw, bone cement can be injected into the affected area through the through hole of the screw, and then the screw can be screwed into the bone cement. After injecting the bone cement, there is no need to reattach the screwdriver, and the screwdriver can be operated as is, so the screw can be quickly screwed in before the bone cement hardens.

[0009] On the other hand, conventional screws, such as those described in Patent Document 1, are not designed to be screwed into pre-injected bone cement. Instead, after screwing the screw in, cement or the like is injected around it through an opening in the side wall to reinforce the surrounding bone. Therefore, the screw's threads are basically engaged with bone, and it is thought that the screw can be removed relatively easily by rotating the screw in the reverse direction. However, if removal is expected to be difficult, a screw and removal tool designed for removal, such as those described in Patent Document 2, would be used.

[0010] The inventors of the present invention have conducted a more in-depth investigation into the risk of screws becoming stuck in bone cement too tightly, making removal difficult. They discovered that this risk becomes apparent when the bond between the bone cement and the screw is stronger than the fusion between the bone cement and surrounding tissues such as bone. In such cases, they realized that using a removal tool like the one described in Patent Document 2 would not solve the problem. While such a removal tool can strongly connect the screw and the driver and transmit strong force to the screw, thus assisting removal when the surrounding area is the patient's bone or other tissue, if the bond between the bone cement and the screw is stronger than the fusion between the bone cement and surrounding tissues such as bone, as described above, the bone cement may separate from the surrounding tissue instead of the screw coming out of the bone cement, thus failing to assist in removal.

[0011] Therefore, to solve this problem, the inventor invented an internal fixation device that is easy to remove and filed an international application as PCT / JP2023 / 022593. This internal fixation device is an alternative to the aforementioned screw, and instead of threads, grooves are formed in the part that is inserted into the bone cement. When a screw is inserted into the bone cement, it pushes and spreads the surrounding bone cement as it advances, so no gaps are created. In contrast, in a groove, the bone cement only fills in due to its viscosity, so a gap is created, or even if no gap is created, the adhesion with the bone cement is weak. Therefore, removal requires little force.

[0012] Here, the term "internal fixation device" is redefined as a device that is inserted from the pedicle into the bone cement inside the vertebral body, supporting and internally fixing the bone cement from the pedicle side within the vertebral body, and includes the aforementioned screws.

[0013] The inventors of the present invention have noticed a further new problem. When inserting an internal fixation device into bone cement, it is generally screwed in using the tapping screw threads (at least the screw threads on the head side for screwing into the pedicle), but when removing it, the internal fixation device is removed by rotating it in the opposite direction to when it was screwed in. However, if the bond between the internal fixation device and the bone cement is stronger than the fusion between the bone cement and the surrounding bone and other affected tissues, there is a problem in that the bone cement rotates and the device cannot be removed.

[0014] The objective of the present invention is to provide a therapeutic device that assists in the removal of an internal fixation device inserted from the pedicle into bone cement that has been pre-filled inside the vertebral body.

[0015] The means for solving these problems are described below, but other problems and novel features will become clear from the description and accompanying drawings in this specification. [Means for solving the problem]

[0016] According to one embodiment of the present invention, the following applies:

[0017] That is, it is a treatment instrument comprising a bone cement molding instrument and a bone cement fixing instrument, which is inserted into an internal fixation instrument that supports and internally fixes the bone cement filled in the vertebral body from the pedicle of the vertebral arch, and is configured as follows. The internal fixation instrument has a through hole in the central axis direction from the head to the tip, is inserted into the bone cement along its central axis, and can be removed. The bone cement molding instrument is inserted into the bone cement through the through hole of the internal fixation instrument to form a hole of a predetermined shape. The bone cement fixing instrument has a tip portion to be inserted into the hole formed above, and by inserting the tip portion into the hole through the through hole of the internal fixation instrument, rotation and / or movement of the bone cement in the pulling-out direction is suppressed.

Advantages of the Invention

[0018] The effects obtained by the above-described embodiment will be briefly described as follows.

[0019] That is, it is possible to provide a treatment instrument that supports the removal of an internal fixation instrument inserted from the pedicle of the vertebral arch into the bone cement previously filled in the vertebral body.

Brief Description of the Drawings

[0020] [Figure 1] FIG. 1 is an explanatory view schematically showing a cross-sectional structure for showing a configuration example of the treatment instrument of the present invention including a bone cement molding instrument. [Figure 2] FIG. 2 is an explanatory view schematically showing a cross-sectional structure for showing a configuration example of the treatment instrument of the present invention including a bone cement fixing instrument. [Figure 3] FIG. 3 is an explanatory view showing the bottom surface of each tip portion (quadrilateral) as viewed from the proximal end side for showing a first configuration example of the bone cement molding instrument and the bone cement fixing instrument. [Figure 4] FIG. 4 is an explanatory view showing the bottom surface of each tip portion (star shape) as viewed from the proximal end side for showing a third configuration example of the bone cement molding instrument and the bone cement fixing instrument. [Figure 5]FIG. 5 is an explanatory diagram showing the appearance and cross-sectional structure of the tip portions of a bone cement molding instrument and a bone cement fixing instrument, respectively, as seen from above. [Figure 6] FIG. 6 is an explanatory diagram showing the bottom surface and cross-sectional structure of the tip portions of a bone cement molding instrument and a bone cement fixing instrument, respectively, as seen from above, for showing a second configuration example. [Figure 7] FIG. 7 is an explanatory diagram showing an example of the use of an internal fixation instrument according to the present invention as seen from above. [Figure 8] FIG. 8 is a top view, a front view, and a bottom view showing a configuration example of an internal fixation instrument according to the present invention. [Figure 9] FIG. 9 is an explanatory diagram schematically showing a cross-sectional structure for showing a configuration example of a treatment instrument according to the present invention. [Figure 10] FIG. 10 is an explanatory diagram schematically showing the first half of the procedure for implanting an internal fixation instrument in the treatment using the treatment instrument of the present invention. [Figure 11] FIG. 11 is an explanatory diagram schematically showing an example of the second half of the procedure for implanting an internal fixation instrument in the treatment using the treatment instrument of the present invention. [Figure 12] FIG. 12 is an explanatory diagram schematically showing another example of the second half of the procedure for implanting an internal fixation instrument in the treatment using the treatment instrument of the present invention. [Figure 13] FIG. 13 is an explanatory diagram schematically showing an example of the procedure for removing an internal fixation instrument in the treatment using the treatment instrument of the present invention. [Figure 14] FIG. 14 is an explanatory diagram schematically showing another example of the procedure for removing an internal fixation instrument in the treatment using the treatment instrument of the present invention. [Figure 15] FIG. 15 is an explanatory diagram showing the bottom surface of the tip portions (cross-shaped) of a bone cement molding instrument and a bone cement fixing instrument, respectively, as seen from the proximal end side, for showing a fourth configuration example. [Figure 16] FIG. 16 is an explanatory diagram showing the appearance and cross-sectional structure of the tip portions of a bone cement molding instrument and a bone cement fixing instrument, respectively, as seen from above, for showing a fifth configuration example. [Figure 17]Figure 17 is an explanatory diagram showing the external appearance and cross-sectional structure of the tip of each bone cement molding instrument and bone cement fixation instrument, in order to illustrate a sixth example of their configuration. [Figure 18] Figure 18 is a schematic diagram illustrating an example of the procedure for removing an internal fixation device during treatment using a therapeutic device according to the third embodiment of the present invention. [Figure 19] Figure 19 is a schematic diagram illustrating another example of the procedure for removing an internal fixation device during treatment using the therapeutic device of the third embodiment of the present invention. [Figure 20] Figure 20 is a schematic explanatory diagram showing examples of the configuration of a bone cement molding device and a driver according to the fourth and fifth embodiments of the present invention. [Figure 21] Figure 21 is a schematic diagram illustrating the latter half of the procedure for implanting an internal fixation device in a treatment using the treatment device of the fifth embodiment. [Figure 22] Figure 22 is a schematic diagram illustrating an example of the procedure for removing an internal fixation device during treatment using the treatment device of the sixth embodiment of the present invention. [Modes for carrying out the invention]

[0021] 1. Overview of the Embodiment First, a general overview of the representative embodiments disclosed in this application will be provided. The reference numerals in parentheses in the drawings used to refer to the representative embodiments are merely illustrative examples of components included in the concept of the elements to which they are attached.

[0022] In this specification, "proximal" refers to the side closer to the midline of the patient's body, and "distal" refers to the side further away; these are medical terms. Bone cement is a medical cement, for example, mainly composed of calcium phosphate and polymethyl methacrylate, and hardens over time.

[0023] [1] Extraction support device to suppress rotation / extraction of bone cement (Figures 1-5, 15-17, 20) A typical embodiment disclosed in this application is a therapeutic device (100) comprising a bone cement molding device (50) and a bone cement fixing device (60) that are inserted into an internal fixation device (10) that supports and internally fixes bone cement filled in the vertebral body from the pedicle, and is configured as follows.

[0024] The internal fixation device has a through hole (16) in the direction of the central axis, extending from the head (13) to the tip, and can be inserted into and removed from the bone cement (1) along the central axis.

[0025] The bone cement molding device is inserted into the bone cement through the through-hole of the internal fixing device to form a hole (2) of a predetermined shape.

[0026] The bone cement fixation device has a tip (61) that is inserted into the hole, and when the tip is inserted into the bone cement (1) through the through hole of the internal fixation device, the rotation of the bone cement around the central axis and / or movement in the withdrawal direction is suppressed.

[0027] This makes it possible to provide a treatment device that assists in the removal of internal fixation devices that are inserted from the pedicle into bone cement pre-filled inside the vertebral body to support and fix the bone cement.

[0028] [2] The tapping screw threads of the bone cement fixation device are screwed into the circular hole for fixation (Figures 16, 17). In the treatment device of [1], the tip of the bone cement molding device is cylindrical (Figure 16) or cylindrical tapered (Figure 17) with a diameter decreasing towards the tip. A cylindrical or cylindrical tapered hole (2) with a diameter decreasing in the depth direction is formed. The bone cement fixing device has screw threads that are tapped into the side wall of the hole.

[0029] This allows the bone cement fixation device to suppress both rotational and withdrawal movements of the bone cement.

[0030] [3] The bone cement molding instrument also has a screw thread on the side wall for tapping (Figure 20) In the treatment device of [2], the bone cement molding device has a screw thread (54) that is tapped into the side wall of the hole and screwed in.

[0031] This allows for the formation of a hole with pre-cut grooves on the side wall. When it becomes necessary to remove the internal fixation device, the tapping threads of the bone cement fixation device are screwed into the grooves pre-formed in the hole, allowing for easy removal with minimal force. Furthermore, it becomes easier to remove the bone cement fixation device after the internal fixation device has been removed.

[0032] [4] Driver (Figures 1, 2, and 20) In [2] or [3], the treatment device (100) further includes a driver (20), the internal fixation device is connectable to the driver at its head (13), and the driver has a through hole that communicates with a through hole of the internal fixation device when connected to the internal fixation device, and through which the tip portions of the bone cement molding device and the bone cement fixation device can pass.

[0033] This provides a screwdriver (20) that can be used in both the surgery to screw in the internal fixation device (10) and the surgery to remove it.

[0034] [5] The bone cement molding device can be connected to a screwdriver (Figure 20). In the treatment device of [4], the bone cement molding device is inserted into the through hole of the screwdriver connected to the internal fixation device, and a predetermined length protrudes from the tip of the internal fixation device.

[0035] This allows the bone cement molding instrument to be inserted and a hole formed while the driver and internal fixation device are connected, thus reducing the number of steps in the procedure.

[0036] [6] The bone cement molding instrument and the screwdriver are detachable (Figure 20). In the treatment device of [5], the bone cement molding device is detachably connected to the driver.

[0037] This allows for the selective use of either simultaneously or separately, the formation of the hole and the insertion of the internal fixation device into the bone cement.

[0038] [7] The bone cement molding instrument and the screwdriver are integrated with a screw (Figure 20) In the treatment device of [6], the driver has a screw structure (53) at its distal end that can be connected to the bone cement molding device.

[0039] This improves the operability of the treatment physician's instruments when simultaneously shaping holes and inserting internal fixation devices into bone cement.

[0040] [8] The bone cement fixation device has a detachable handle (Figure 14). In any one of the treatment devices described in [2] to [7], the bone cement fixation device has a structure in which the handle portion (62) and the shaft portion are detachable.

[0041] This allows the handle to be attached to prevent rotation of the bone cement fixation device and removed when the bone cement fixation device is removed, thereby improving the flexibility of the procedure.

[0042] [9] Guide pin (Figure 22) In any one of paragraphs (2) to (8), the treatment device further includes a guide pin (40), and the bone cement fixation device has a through hole (64) through which the guide pin can pass.

[0043] This allows the bone cement fixation device to be guided into the bone cement hole in the affected area by following the guide pin that has been inserted into the affected area beforehand.

[0044]

[10] A bone cement fixing device that contacts the side wall of a square-shaped hole to suppress the rotation of the bone cement (Figure 5) In the treatment device of [1], the tip of the bone cement molding device is a prismatic shape (Figure 5(a)) or a tapered prismatic shape with a smaller cross-section towards the tip (Figure 5(b)), and a hole (2) is formed in the shape of a prismatic or tapered prismatic shape with a smaller cross-section in the depth direction. The bone cement fixing device has a tip shape that can contact the side wall of the hole to suppress the rotation of the bone cement.

[0045] This allows the bone cement fixation device to abut against the side wall of the hole, preventing the bone cement from rotating. Since the bone cement fixation device is simply inserted into the hole, it can be easily removed.

[0046]

[11] The bone cement fixation device has a detachable handle (Figure 14). In the treatment device of

[10] , the bone cement fixation device has a structure in which the handle portion (62) and the shaft portion are detachable.

[0047] This allows the handle to be attached to prevent rotation of the bone cement fixation device and removed when the bone cement fixation device is removed, thereby improving the flexibility of the procedure.

[0048]

[12] Driver In

[10] or

[11] , the treatment device further includes a screwdriver, the internal fixation device is connectable to the screwdriver at its head, and the screwdriver has a through-hole that communicates with the through-hole of the internal fixation device when connected to the internal fixation device, and through which the bone cement molding device and the tip portion of the bone cement fixation device can pass.

[0049] This provides a screwdriver (20) that can be used in both the surgery to screw in the internal fixation device (10) and the surgery to remove it.

[0050]

[13] Guide pin (Figure 22) In any one of paragraphs

[10] to

[12] , the treatment device further includes a guide pin (40), and the bone cement fixation device has a through hole (64) through which the guide pin can pass.

[0051] This allows the bone cement fixation device to be guided into the bone cement hole in the affected area by following the guide pin that has been inserted into the affected area beforehand.

[0052] 2. Details of the Embodiment The embodiments will be described in more detail.

[0053] [Embodiment 1] Figure 7 is an explanatory diagram showing an overview of an example of the use of the internal fixation device 10. In a standing position, the spine is composed of multiple vertebral bodies 90 stacked vertically, and Figure 7 shows one of these vertebral bodies 90 as if viewed from above or below. The vertebral body 90 is supported by a pair of pedicles 91, and these pedicles 91 are connected by a vertebral arch 92. The area enclosed by the vertebral body 90, pedicles 91, and vertebral arch 92 is the spinal canal 93. A compression fracture is a disease in which the vertebral body is compressed and collapsed by an upward or downward force. In treatment using the internal fixation device 10 according to the present invention, as will be described later with reference to Figures 10 and 11, space is restored inside the vertebral body 90 and bone cement 1 is injected. Before it hardens, the internal fixation device 10 is inserted (screwed in) to support it from the pedicle 91 side. In other words, the internal fixation device 10 is inserted from the pedicle 91 into the bone cement 1 that has been pre-filled inside the vertebral body 90, and once the bone cement 1 hardens, it is supported by the internal fixation device 10 from the pedicle 91 and fixed inside the vertebral body 90. At this time, the internal fixation device 10 according to the present invention is a device that is screwed into the bone cement 1 inside the vertebral body 90 while tapping the bone hole formed in the pedicle 91, and may be a conventional screw such as the one described in Patent Document 1, but the tip side that is embedded in the bone cement 1 does not necessarily need to have tapping threads.

[0054] Figure 8 shows a top view (a), a front view (b), and a bottom view (c) illustrating an example configuration of an easily removable internal fixation device 10, which was internationally filed as PCT / JP2023 / 22593. The rear view and left and right side views are the same as the front view (b), except that the groove 14 and screw threads 15 are positioned as extensions from the front view (b), and are therefore omitted from the illustration. The internal fixation device 10 comprises a cylindrical shaft 12 and a connecting portion 13 at the distal end of the shaft 12 that can be connected to a screwdriver. The shaft 12 has a spiral groove 14 on its proximal side. Preferably, the shaft 12 is cylindrical, as illustrated in the figure, and has a through hole 16 that penetrates from the distal end to the proximal end along the central axis. The through hole 16 can, for example, pass a guide pin through it. The through hole 16 may also be configured to allow the passage of a bone drilling instrument, balloon catheter, bone cement injector, etc. The head connection portion 13 is configured as a hexagonal prism-shaped recess that engages with a screwdriver (not shown) to allow the entire internal fixing device 10 to rotate. For example, it is designed to engage with a hexagonal wrench. Figure 8 shows an example of a hexagonal prism-shaped head (connecting portion) assuming connection to a hexagonal wrench-shaped screwdriver head, but this shape is arbitrary as long as it can transmit rotational force, and may be changed to, for example, a star shape, triangle, square, or cross shape. In this specification, reference numeral 13 may be referred to as the "head" when emphasizing its position in the internal fixing device 10, or as the "connecting portion" when emphasizing its function of connecting to a screwdriver.

[0055] The depth of the groove 14 of the internal fixation device 10 may be uniform, but it is preferable to make the proximal (tip) side deeper than the distal (head) side of the shaft 12. When the internal fixation device 10 is screwed into the bone cement 1 while rotating along the spiral of the groove 14, the proximal (tip) side that first contacts the bone cement 1 is deeper, so the bone cement 1 enters deeper into the groove 14 and, as it is screwed in, is sent along the spiral of the groove 14 to the shallower distal (head) side of the groove 14, so that the bone cement 1 enters the groove 14 smoothly and is firmly fixed. On the other hand, when removing the device, the internal fixation device 10 rotates in the opposite direction along the spiral of the groove 14 as it separates from the bone cement 1, so that the force required for removal can be reduced.

[0056] The shaft 12 of the internal fixation device 10 is more preferably provided with a sloping section 17 whose diameter gradually decreases from the central part towards the proximal end. When screwing the internal fixation device 10 into the bone cement 1, the resistance when initially inserting it into the bone cement 1 is reduced, and the force required when removing it is also reduced.

[0057] The distal (head) end of the shaft 12 of the internal fixation device 10 is preferably provided with a screw thread 15. The screw thread 15 is a spiral projection that protrudes outward from the outer surface of the shaft 12, and has the function of tapping the surrounding bone as the internal fixation device 10 (shaft 12) rotates, thereby advancing along the central axis. The screw thread 15 taps the pedicle 91 as it advances, firmly fixing the internal fixation device 10 and stably supporting the bone cement 1 inside the vertebral body 90 into which the shaft 12 is inserted.

[0058] Preferably, the screw threads 15 and the groove 14 are formed with equal leads. The lead is the distance traveled along the central axis with respect to the amount of rotation of the shaft 12, and it is desirable that the distance traveled by the shaft 12 as the screw threads 15 tap the pedicle 91 matches the distance traveled by the shaft 12 along the spiral of the groove 14 when it is screwed into the bone cement 1. However, a precise match is not necessarily required, and they can be intentionally made different. For example, by making the lead of the groove 14 larger than the lead of the screw threads 15, the groove 14 at the tip of the shaft 12 can be partially screwed into the bone cement 1, and after the screw threads 15 begin tapping the pedicle, a force can be applied that brings the bone cement 1 closer to the pedicle as the internal fixation device 10 (shaft 12) rotates.

[0059] The number of grooves in the groove 14 and the number of threads in the screw thread 15 can be different. For example, the number of grooves in the groove 14 should be smaller than the number of threads in the screw thread 15. This allows for a firm fixation to the pedicle 91 by the screw thread 15 while appropriately designing the bonding force between the internal fixation device 10 and the bone cement 1. As mentioned above, it is preferable to have equal leads for the groove 14 and the screw thread 15. In this case, a new challenge arises: appropriately setting the contact area with the object. This challenge can be solved by designing the number of grooves independently. Reducing the number of grooves in the groove 14 reduces the contact area with the bone cement 1, thereby weakening the force required for removal. On the other hand, increasing the contact area between the pedicle 91 and the screw thread 15 strengthens the fixation of the internal fixation device 10 to the pedicle 91. By optimizing the number of grooves rather than the pitch, the relationship between the bone cement 1 and the groove 14, and the relationship between the pedicle 91 and the screw thread 15 can be optimized independently.

[0060] In this specification, "internal fixation device" refers to a device that is inserted from the pedicle into bone cement pre-filled within the vertebral body, and which, once the bone cement hardens, is fixed from the pedicle into the bone cement within the vertebral body. Therefore, the internal fixation devices in this specification include not only the easily removable internal fixation device 10 for which an international application was filed as PCT / JP2023 / 022593, but also devices without grooves 14, devices without threads 15, devices without both grooves 14 and threads 15, and even conventional screws with threads formed throughout.

[0061] Figure 9 is an explanatory diagram illustrating a schematic cross-sectional structure to show an example of the configuration of the treatment device 100. Figure 9 is drawn with a compressed scale in the central axis direction (vertical direction on the paper) and emphasis on the direction along the patient's body surface (horizontal direction on the paper). The treatment device 100 includes a cylindrical driver 20 that can screw the internal fixation device 10 into the bone, and an inner cylinder 30 that is inserted into the driver 20, and is configured as follows.

[0062] The internal fixation device 10 has a blunt tip that allows for the insertion and removal of soft vertebral excavation equipment such as balloons, and has a screw thread 15 on its outer wall that can tap bone or cement, and a through hole 16 through which the inner cylinder 30 can pass from the head 13 to the tip along the central axis. The screwdriver 20 is connected to the internal fixation device 10 by fitting into the head 13 of the internal fixation device 10 when moved along the central axis, and is configured to transmit rotational force around the central axis to the internal fixation device 10. For example, the tip of the screwdriver 20 may have the shape of a hexagonal wrench (hexagonal prism), and the head 13 of the internal fixation device 10 may have a hexagonal groove (recess). As described above with reference to Figure 8, the shape of the screwdriver tip and the shape of the screw head only need to mesh when inserted, and shapes other than hexagons, such as a star shape, are also acceptable. By sliding the screwdriver 20 along the central axis onto the head of the internal fixing device 10, the tip of the screwdriver 20 will fit into the head 13 of the internal fixing device 10, allowing the screwdriver 20 to be screwed in, and the screwdriver 20 can be easily removed by pulling it out.

[0063] The inner cylinder 30 is inserted from the distal end of the screwdriver 20 through the through-hole of the screwdriver 20 and the internal fixing device 10, and has a tip portion 32 that protrudes proximally to the tip of the internal fixing device 10. With the tip portion 32 protruding proximally to the tip of the internal fixing device 10, the inner cylinder 30 is connected to and integrated with the internal fixing device 10 and the screwdriver 20, improving operability such as screwing in the internal fixing device 10. Furthermore, the insertion of the guide pin 40 strengthens the integration, making it impossible to pull the inner cylinder 30 out of the internal fixing device 10 and the screwdriver 20.

[0064] An example of a structure for integrating the internal fixing device 10, the driver 20, and the inner cylinder 30 will be described.

[0065] The tip 32 of the inner cylinder 30 is divided into a plurality of tongue pieces 31 in the direction along the central axis, and each of the plurality of tongue pieces 31 has a protrusion 33 in the direction away from the central axis. The protrusion 33 has the function of a notch that restricts the inner fixing device 10 from coming out of the inner cylinder 30, as described later, so the reference numeral 33 is used to refer to a notch. The plurality of tongue pieces 31 are formed, for example, by dividing the cylindrical inner cylinder 30 with slits from the tip side. The number of divisions can be arbitrary, for example, 4 divisions, 6 divisions, 2 divisions, 3 divisions, etc. In addition, some processing (for example, heat treatment, processing to reduce thickness, processing to bond a highly elastic metal) may be applied to give it appropriate elasticity. The elasticity of the tongue pieces 31 is designed to have appropriate deflection. For example, when the inner cylinder 30 passes through the through hole of the screwdriver 20, the notch 33 is pressed against the inner wall of the through hole, causing it to bend in the axial direction and allowing the inner cylinder 30 to pass through. When the notch 33 emerges proximal to the tip of the internal fixing device 10, the bending returns to its original position, causing the notch 33 to catch on the tip of the internal fixing device 10. If the notch 33 has a smooth shape, even after the notch 33 emerges from the tip of the internal fixing device 10, the force pulling out the inner cylinder 30 can pull the notch 33 back into the through hole 16 of the internal fixing device 10, causing the tongue 31 to bend again in the axial direction, thereby allowing the inner cylinder 30 to be pulled out. When the guide pin 40 is inserted, the tongue 31 cannot bend in the axial direction, making it impossible to pull the inner cylinder 30 out of the internal fixing device 10 and the screwdriver 20.

[0066] Furthermore, as shown in Figure 9, it is preferable that the driver 20 and the inner cylinder 30 be configured to be connected at their distal ends. The distal end of the driver 20 is provided with a cylindrical connecting portion 25 having male threads 26 on its outer surface, and the distal end of the inner cylinder 30 is provided with a groove-shaped connecting portion 35 that can accommodate the cylinder, and a female thread 36 that engages with the male threads 26 is formed therein. The relationship between the concave and concave parts, and the relationship between the male and female threads, may be reversed, or other connection mechanisms may be used. Also, as illustrated in Figure 9, it is preferable that the driver 20 is provided with a handle 27 and the inner cylinder 30 is provided with a handle 37, so that they are integrated for easy gripping when connected. Even if the connection is made with screws as in this example, a latch mechanism (not shown) may be provided to prevent the connection from coming undone.

[0067] The treatment device 100 of the present invention comprises a bone cement molding device 50 and a bone cement fixing device 60, which are inserted into an internal fixation device 10 that supports and internally fixes bone cement filled inside the vertebral body from the pedicle, and is configured as follows.

[0068] First, as a premise, the internal fixation device 10 has a through hole 16 in the direction of the central axis, extending from the head 13 to the tip (proximal end), and is configured to be inserted into and removed from the bone cement 1 along the central axis. For example, please refer to the above explanation with reference to Figure 8.

[0069] Figure 1 is a schematic diagram illustrating the cross-sectional structure to show an example of the configuration of the treatment instrument 100 of the present invention, including the bone cement molding instrument 50. Figure 1 is drawn with a compressed scale in the central axis direction (vertical direction of the paper) and emphasis on the direction along the patient's body surface (horizontal direction of the paper). The internal fixation device 10 and the driver 20 each have through holes along their central axes, and are configured so that their through holes communicate with each other when connected. The bone cement molding instrument 50 is inserted from its distal end into the through hole that communicates when the internal fixation device 10 and the driver 20 are connected, and its tip portion 51 is configured to protrude proximally from the tip of the internal fixation device 10. The bone cement molding instrument 50 is inserted into the bone cement 10 through the through hole 16 after the internal fixation device 10 has been inserted into the bone cement 1, forming a hole 2 of a predetermined shape. The bone cement molding instrument 50 shown in Figure 1 is equipped with a handle 52, but it is not important to rotate the bone cement molding instrument 50; the important function is to prevent the tip 51 from going in too deeply, so the handle shape is not necessary. The tip 51 is designed to protrude from the tip of the internal fixation device 10 to a desired depth when forming the hole 2 in the bone cement 1. The desired depth is arbitrary, for example, about 1 cm. To determine the amount of protrusion, a scale can be engraved or printed on the distal end of the shaft of the bone cement molding instrument 50, and a stopper with a diameter larger than the through-hole of the screwdriver 20 can be provided to prevent extreme protrusion. Alternatively, the position in which the handle 52 is attached can be adjusted to function as this stopper. Or, if the bone cement molding instrument 50 is structured to be connected to the screwdriver 20 with a screw or the like, the internal fixation device 10 can be screwed into the bone cement at the same time as forming the hole 2. Even if the depth of hole 2 is not controlled by the bone cement molding instrument 50 alone, the structure is such that if the instrument is inserted to a depth that is expected to be the length of the internal fixation device 10, hole 2 will naturally form to a predetermined depth (for example, 1 cm deeper than the tip of the internal fixation device 10).

[0070] Figure 2 is a schematic diagram illustrating the cross-sectional structure to show an example of the configuration of the treatment device of the present invention, including the bone cement fixation device 60. Similar to Figure 1, the scale in the central axis direction (vertical direction on the paper) is compressed, and the direction along the patient's body surface (horizontal direction on the paper) is emphasized in the drawing. The bone cement fixation device 60, like the bone cement molding device 50, is inserted from its distal end into a through-hole that communicates when the internal fixation device 10 and the driver 20 are connected, and its tip portion 61 is configured to protrude proximally from the tip of the internal fixation device 10. The communicating through-hole has a circular cross-section, and the bone cement fixation device 60 that is inserted also has a circular cross-section, and their rotational movements are configured so as not to interfere with each other. In simpler terms, the bone cement fixation device 60 does not rotate even when the driver 20 is turned. The bone cement fixation device 60 has a tip portion 61 that is inserted into the hole 2 formed by the bone cement molding device 50. The tip portion 61 has, for example, the same shape as the predetermined shape described above, and is inserted into the bone cement 1 through the through hole 16 of the internal fixing device 10, where a hole 2 has been formed. By inserting the tip portion 61 into the hole 2, rotation of the bone cement 1 around its central axis is suppressed. Here, "same shape" does not mean that the size is exactly the same without any error. It is sufficient that the tip portion 61 of the bone cement fixing device 60 fits into the hole 2 formed by the tip portion 51 of the bone cement molding device 50, thereby inhibiting the rotation of the bone cement 1. In fact, it is desirable that there be enough clearance to allow for smooth insertion. This is true throughout this specification. Since the tip portion 61 of the bone cement fixing device 60 only needs to fit into the hole 2 formed by the tip portion 51 of the bone cement molding device 50, "same shape" is a sufficient condition but not a necessary one, and various shapes can be used as described later. Furthermore, when the tip 61 of the bone cement fixing device 60 is fitted into the hole 2 formed by the tip 51 of the bone cement molding device 50, the tip comes into contact with the bottom of the hole 2, thereby suppressing movement in the direction of pulling out the bone cement 1.

[0071] This makes it possible to provide a treatment device that assists in the removal of an internal fixation device that is inserted from the pedicle into bone cement 10 that has been pre-filled inside the vertebral body.

[0072] The bone cement fixation device 60 is more preferably provided with a handle 62 at its distal end. As described above, the screwdriver 20 and the inserted bone cement fixation device 60 are configured so that their rotational movements do not interfere with each other. Therefore, when the screwdriver 20 is rotated, the handle 62 can be used to hold the bone cement fixation device 60 in place so that it does not rotate together with the screwdriver 20. Furthermore, this handle 62 may be configured to be detachable, as will be described later.

[0073] Figure 2 shows the tip 61 of the bone cement fixation device 60 protruding slightly from the tip of the internal fixation device 10, with the handle 62 in contact with the distal end of the screwdriver 20. However, in reality, the length of the bone cement fixation device 60 is longer than shown in the illustration. As will be described later with reference to Figure 13, with the tip 61 of the bone cement fixation device 60 inserted into the hole 2 of the bone cement 1, the handle 62 is positioned distally away to remove the internal fixation device 10 (see Figures 13

[24] and

[25] ). When the screwdriver 20 and the internal fixation device 10 are connected, a scale indicating how much the tip 61 of the bone cement fixation device 60 protrudes beyond the tip of the internal fixation device 10 may be provided on the distal side of the bone cement fixation device 60. When the bone cement fixation device 60 is inserted into the internal fixation device 10 before removal, the insertion of the bone cement fixation device 60 stops within the hole 2 formed in the bone cement 1. However, even if the bone cement 1 is damaged and the device does not stop within the hole 2, a warning can be issued to prevent insertion beyond the intended length and damage to surrounding tissues. A stopper mechanism may also be installed to prevent excessive insertion.

[0074] The shape of the tip 51 of the bone cement molding instrument 50 and the tip 61 of the bone cement fixing instrument 60 will be described in more detail. For example, the "predetermined shape" is preferably a prismatic shape.

[0075] Figures 3 and 5 are explanatory diagrams showing the tip portions of the bone cement molding instrument 50 and bone cement fixation instrument 60 to illustrate their respective configurations ((a) is the tip portion 51 of the bone cement molding instrument 50, and (b) is the tip portion 61 of the bone cement fixation instrument 60). Figure 3 shows the bottom view from the proximal end, and Figure 5 shows the external appearance and cross-sectional structure of each tip portion from an overhead view. As an example, the bone cement molding instrument 50 has a cylindrical shaft and a rectangular prism tip portion 51, and the bone cement fixation instrument 60 has a cylindrical shaft and a rectangular prism tip portion 61. As shown in the figures, it is preferable for the tip portion 61 of the bone cement fixation instrument 60 to have a further rectangular pyramidal portion at the end of the rectangular prism, as this allows for smoother insertion. The diameter d50 of the cylindrical shaft of the bone cement molding instrument 50 is slightly smaller than the diameter d10 of the through hole 16 of the bone cement 10, and the rectangular prism of the tip portion 51 is formed inside it. For example, the length d51 of the diagonal of the square in the cross-section of the square prism is equal to or less than d50. The bone cement fixing device 60 has a cylindrical shaft and a square prism-shaped tip 61. The diameter d60 of the cylindrical shaft of the bone cement fixing device 60 is slightly smaller than the diameter d10 of the through hole 16 of the bone cement 10, and the square prism of the tip 61 is formed inside it. For example, the length d61 of the diagonal of the square in the cross-section of the square prism is equal to or less than d51, and it is preferable that it be sized to fit approximately snugly into the hole 2 formed by the tip 51 of the bone cement molding device 50. It is sufficient that it fits snugly and prevents the bone cement 1 from rotating, so it does not need to fit snugly and some clearance is acceptable.

[0076] As a result, the bone cement fixing device 60 can suppress the rotation of the bone cement simply by inserting it into the hole formed in the bone cement 1.

[0077] Although a rectangular prism was used as an example, other shapes are also acceptable. Triangular prisms, pentagonal prisms, hexagonal prisms, and even star-shaped, plate-shaped, or cross-shaped plate-shaped designs are all possible. The bone cement molding instrument 50 and the bone cement fixing instrument 60 should have the same shaped tip, and the tip 61 of the bone cement fixing instrument 60 should fit into the hole 2 formed by the bone cement molding instrument 50 to suppress rotational movement. Figure 4 is an explanatory diagram showing the bottom surface of each tip (star-shaped) as viewed from the proximal end, illustrating another example of the configuration of the bone cement molding instrument 50 and the bone cement fixing instrument 60.

[0078] Furthermore, Figure 5 shows an example in which the bone cement molding instrument 50 and the bone cement fixing instrument 60 have the same rectangular prism-shaped tip and fit together snugly, suppressing rotational movement. As shown in the cross-sectional structure of Figure 5(c), the tip of the bone cement fixing instrument 60 contacts the bottom of the hole 2, which also suppresses movement in the direction that would pull out the bone cement 1, but it is understood that the suppression of rotation is the primary effect.

[0079] Figure 6 is an explanatory diagram showing the bottom and cross-sectional structures of the tips of the bone cement molding instrument 50 and the bone cement fixing instrument 60, in order to illustrate another configuration example of the bone cement molding instrument 50 and the bone cement fixing instrument 60. The tips 51 of the bone cement molding instrument 50 and the tips 61 of the bone cement fixing instrument 60 are each prism tapered, with a square pyramid formed at the end of a square prism. The tip 51 of the bone cement molding instrument 50 is more acute than the tip 61 of the bone cement fixing instrument 60, and as shown in the cross-sectional structure of Figure 6(c), the tip 61 of the bone cement fixing instrument 60 is structured to abut and fit into the side wall of the hole 2 formed by the tip 51 of the bone cement molding instrument 50 before reaching the bottom of the hole 2. This suppresses both rotational and withdrawal movements.

[0080] In Figures 5 and 6, the tip of the cone is depicted as sharp to aid understanding, but it is preferable that the tip be blunted to prevent damage to body tissues, nerves, or blood vessels.

[0081] Furthermore, as will be described later in Embodiments 2 and 3, the tip 61 of the bone cement fixing device 60 does not need to have the same shape as the tip 51 of the bone cement molding device 50; it is sufficient that it can fit into the hole 2 formed in the bone cement 1 by the bone cement molding device 50 and suppress the rotation of the bone cement 1.

[0082] The surgical procedure using the therapeutic device 100 of the present invention will be described.

[0083] Figures 10 and 11 are schematic diagrams illustrating the procedure for implanting the internal fixation device 10 as part of treatment using the treatment device 100. Figure 10 shows the first half of the procedure, and Figure 11 shows the second half. Although Figures 10 and 11 illustrate vertebroplasty, the method of inserting the internal fixation device 10 into the vertebral body is similar in spinal fusion surgery and vertebral reinforcement surgery in artificial disc replacement (not illustrated). Figures 10 and 11 schematically show a cross-section of the affected area of ​​the patient, with the upper side of the paper being distal and the lower side being proximal, from the outside of the skin 94 through the pedicle 91 to the vertebral body 90. The scale in the central axis direction (vertical direction of the paper) has been compressed, and the direction along the patient's body surface (horizontal direction of the paper) has been emphasized. Since there are pedicles 91 on both the left and right sides of the vertebral body 90, the same procedure is performed on one vertebral body 90 from both sides, but Figures 10 and 11 show one of them.

[0084] Step 1 ([1]): The subcutaneous tissue from the skin 94, which is the surface of the patient's back, to the affected vertebral body 90 is incised and perforated, and the guide pin 40 is introduced through the pedicle 91 to the vertebral body 90.

[0085] Step 2 ([2]): The internal fixation device 10 and the screwdriver 20 are connected, and the inner cylinder 30 is inserted into the through-hole on the inside of the internal fixation device 10 so that the tip 32 protrudes from the tip of the internal fixation device 10. The inner cylinder 30 is then placed over the guide pin 40 and inserted into the patient's body along the guide pin 40.

[0086] Step 3 ([3]): The treatment instrument 100, which consists of the internal fixation device 10, the screwdriver 20, and the inner cylinder 30 connected and integrated, is further pushed proximal along the guide pin 40, twisting the inner cylinder 30 and the tip of the internal fixation device 10 into the pedicle 91.

[0087] Step 4 ([4]): After screwing the internal fixation device 10 in until its tip reaches near the entrance of the vertebral body 90, the guide pin 40 is removed. At this time, the notch 33 of the inner cylinder 30 is in contact with the tip of the internal fixation device 10, preventing the inner cylinder 30 from coming out naturally. However, with the guide pin 40 removed, the tongue 31 bends in the direction of the central axis due to the force pulling out the inner cylinder 30, making it possible to pull out the inner cylinder 30.

[0088] Step 5 ([5]): Remove the inner cylinder 30. At this time, the screwdriver 20 is simply inserted into the head 13 of the internal fixation device 10, so hold it in place to prevent it from coming out. Although not specifically shown in the diagram, in this step, if necessary, a vertebral body drilling device may be introduced through the screwdriver 20 and the through-hole of the internal fixation device 10 to drill into the vertebral body 90 in order to fill with cement for reinforcement.

[0089] Step 6 ([6]): The balloon catheter 70 is introduced into the vertebral body 90 through the through-hole of the driver 20 and the through-hole of the internal fixation device 10, and the balloon 71 is inflated inside the vertebral body 90. For example, the balloon 71 is inflated by injecting contrast agent through the balloon catheter 70 and applying pressure. The purpose is to return the vertebral body 90 to its original size when it has suffered a compression fracture due to osteoporosis or the like.

[0090] Step 7 ([7]): Withdraw the balloon catheter 70 from the driver 20 and the through-hole of the internal fixation device 10, insert the cement injector 80, and inject bone cement 1 into the vertebral body 90. For example, if the capacity of cement that can be filled at one time by the cement injector 80 is approximately 1.5 ml, then in the case of vertebroplasty for fracture, for example, the cement is injected approximately 3 times from each side, for a total of 6 to 7 times, to fill the vertebral body 90 with approximately 10 ml of bone cement 1. When applied to vertebral reinforcement surgeries other than vertebroplasty, such as spinal fusion and artificial disc replacement, the amount of cement to be filled should be adjusted according to the condition of the bone.

[0091] Step 8 ([8]): Remove the cement injector 80 from the screwdriver 20 and the through-hole of the internal fixing device 10.

[0092] Step 9 ([9]): Use the screwdriver 20 to screw the internal fixation device 10 into the filled bone cement 1.

[0093] Step 10 (

[10] ): Insert the bone cement molding instrument 50 into the bone cement 1 through the through-hole of the driver 20 and the through-hole of the internal fixing device 10. The bone cement 1 has not yet hardened, and the tip 51 of the bone cement molding instrument 50 forms a hole 2 of a predetermined shape.

[0094] Step 11 (

[11] ): The bone cement molding instrument 50 and the screwdriver 20 are withdrawn, and the incised skin 94 is sutured to complete the treatment.

[0095] As described above, in the procedure for internally fixing the bone cement 1 with the embedded internal fixation device 10, a crucial part of the present invention is to form a predetermined-shaped hole 2 in the bone cement 1, which has not yet hardened, using the tip 51 of the bone cement molding device 50. Note that the procedure for embedding the internal fixation device described here with reference to Figures 10 and 11 is merely one example. Steps 2 ([2]) to 6 ([6]) may, for example, involve inserting a balloon through another outer cylinder to secure space for filling with bone cement 1, then inserting a thick guide pin, removing the outer cylinder, and inserting the internal fixation device 10 and the screwdriver 20.

[0096] Figure 12 is a schematic diagram illustrating another example of the latter half of the procedure for implanting an internal fixation device in treatment using the therapeutic device of the present invention. The first half (steps 1 to 6) through to step 7 are the same as described above, with reference to Figures 10 and 11.

[0097] Step 8 ([8']): The cement injector 80 is withdrawn from the driver 20 and the through-hole of the internal fixing device 10, and the bone cement molding instrument 50 is inserted. The tip 51 of the bone cement molding instrument 50 forms a hole 2 of a predetermined shape in the bone cement 1.

[0098] Step 9 ([9']): Use the screwdriver 20 to screw the internal fixation device 10 into the filled bone cement 1.

[0099] Step 10 ([10']): Withdraw the bone cement molding instrument 50. A hole 2 of a predetermined shape is molded into the bone cement 1.

[0100] Step 11 (

[11] ): The driver 20 is withdrawn (actually along with the withdrawal of the bone cement molding instrument 50 in Step 10 ([10'])), and the incised skin 94 is sutured to complete the treatment.

[0101] Thus, the formation of a predetermined hole 2 in the bone cement 1 using the bone cement molding instrument 50 can be performed either before or after inserting the internal fixation device 10 into the bone cement 1 using the screwdriver 20. According to the procedure in Figure 11, the formation of the hole 2 by the bone cement molding instrument 50 is performed after the internal fixation device 1 has been inserted into the bone cement 1, so the misalignment between the through hole 16 of the internal fixation device 1 and the hole 2 is minimized. On the other hand, in the procedure in Figure 12, the formation of the hole 2 by the bone cement molding instrument 50 is performed before the bone cement 1 has hardened, and then the internal fixation device 1 can be inserted immediately afterward.

[0102] Next, the procedure for removing the internal fixation device 10 will be described.

[0103] Figure 13 is a schematic diagram illustrating an example of the procedure for removing the internal fixation device 10 during treatment using the therapeutic device of the present invention.

[0104] Initial state (

[21] ): The patient's vertebral body 90 is internally fixed by bone cement 1 being supported by an internal fixation device 10 inserted from the pedicle 91. A hole 2 of a predetermined shape is formed in the bone cement 1 through a through hole 16 of the internal fixation device 10.

[0105] Step 1 (

[22] ): The subcutaneous tissue from the skin 94, which is the surface of the patient's back, to the affected vertebral body 90 is incised and perforated, and a guide pin 40 is inserted into the through-hole 16 of the internal fixation device 10 inserted into the pedicle 91. Figure 13

[22] illustrates how the guide pin 40 has been introduced to the hole 2 formed in the bone cement 1 inside the vertebral body 90, but it is sufficient for the guide pin 40 to reach the through-hole 16 of the internal fixation device 10.

[0106] Step 2 (

[23] ): Guide the screwdriver 20 to the internal fixing device 10 by aligning the through-hole of the screwdriver 20 with the inserted guide pin 40, and connect the tip of the screwdriver 20 by fitting it into the head (connecting part) 13 of the internal fixing device 10.

[0107] Step 3 (

[24] ): The bone cement fixation device 60 is inserted into the through-hole 16 of the internal fixation device 10 and the through-hole 2 of the driver 20, which are connected by the connection between the driver 20 and the internal fixation device 10, and guided into the vertebral body 90, with the tip 61 inserted into the hole 2 of the bone cement 1. The shape of the tip 61 of the bone cement fixation device 60 and the shape of the hole 2 of the bone cement 1 are the same, allowing them to fit together and suppressing rotational movement. Movement in the direction of pulling out the bone cement 1 is suppressed by the tip of the bone cement fixation device 60 contacting the bottom of the hole 2.

[0108] Step 4 (

[25] ): With the tip 61 of the bone cement fixation device 60 fitted into the hole 2 of the bone cement 1 and its movement in the direction of rotation and withdrawal suppressed, the internal fixation device 10 is removed by rotating the screwdriver 20 while holding the bone cement fixation device 60 with the handle 62 to prevent it from rotating. If the screw threads 15 provided on the distal side of the internal fixation device 10 tapped the pedicle 91 during insertion, rotating it in the opposite direction to the insertion direction can provide a thrust force to the internal fixation device 10 in the direction of withdrawal, allowing the internal fixation device 10 to be removed smoothly. Alternatively, if the internal fixation device 10 does not have a structure such as screw threads, it is also possible to tap and remove the internal fixation device 10 using the screwdriver 20 or an instrument such as forceps to grasp the internal fixation device 10 while suppressing its movement in the direction of withdrawal of the bone cement 1 with the bone cement fixation device 60.

[0109] Step 5 (

[26] ): The bone cement fixation device 60 is removed (in practice, together with the internal fixation device 10 and screwdriver 20 from Step 4 (

[25] )), and the incised skin 94 is sutured to complete the treatment. If the tip of the bone cement fixation device 60 and the shape of the hole 2 are both rectangular prisms, etc., it can be removed simply by pulling it out.

[0110] Figure 14 is a schematic diagram illustrating another example of the procedure for removing the internal fixation device 10.

[0111] Initial state (

[31] ): Similar to the initial state (

[21] ) shown in Figure 13, the patient's vertebral body 90 is internally fixed by bone cement 1 being supported by an internal fixation device 10 inserted from the pedicle 91. A predetermined shaped hole 2 is formed in the bone cement 1 through the through hole 16 of the internal fixation device 10.

[0112] Step 1 (

[32] ): The subcutaneous tissue from the skin 94, which is the surface of the patient's back, to the affected vertebral body 90 is incised and perforated, and the bone cement fixation device 60 is directly inserted into the through-hole 16 of the internal fixation device 10 instead of the guide pin 40 shown in

[22] of Figure 13. More specifically, the tip of the bone cement fixation device 60 inserted into the through-hole 20 is introduced into the through-hole 16 of the internal fixation device 10 inserted into the pedicle 91. It is preferable that the bone cement fixation device 60 is configured to have a detachable handle 62. With the handle 62 removed, the bone cement fixation device 60 can be inserted into the through-hole 16 of the internal fixation device 10 in the same way as the guide pin 40, and the driver 20 can be guided from the distal end of the bone cement fixation device 60 along the shaft of the bone cement fixation device 60 to the internal fixation device 10 and connected to the head (connecting part) 13 of the internal fixation device 10.

[0113] Step 2 (

[33] ): Push the screwdriver 20 deeply along the bone cement fixation device 60 and connect it to the head (connecting part) 13 of the internal fixation device 10. Insert the bone cement fixation device 60 further in and insert the tip 61 of the bone cement fixation device 60 into the hole 2 of the bone cement 1. The order of insertion of the screwdriver 20 and the bone cement fixation device 60 is arbitrary, and either can be done first or simultaneously. The tip 61 of the bone cement fixation device 60 and the hole 2 of the bone cement 1 are processed to the same shape, and rotational movement is suppressed when they fit together. Movement in the direction of pulling out the bone cement 1 is suppressed when the tip of the bone cement fixation device 60 abuts against the bottom of the hole 2.

[0114] Step 3 (

[34] ): With the tip 61 of the bone cement fixation device 60 fitted into the hole 2 of the bone cement 1 and its movement in the direction of rotation and withdrawal suppressed, the internal fixation device 10 is removed by rotating the screwdriver 20 while holding the bone cement fixation device 60 with the handle 62 to prevent it from rotating. If the screw threads 15 provided on the distal side of the internal fixation device 10 tapped the pedicle 91 during insertion, rotating it in the opposite direction to the insertion direction can provide a thrust force to the internal fixation device 10 in the direction of withdrawal, allowing the internal fixation device 10 to be removed smoothly. Alternatively, if the internal fixation device 10 does not have a structure such as screw threads, it is also possible to remove the internal fixation device 10 by tapping it up using the screwdriver 20 or an instrument such as forceps to grasp the internal fixation device 10, while suppressing the movement of the bone cement 1 in the direction of withdrawal with the bone cement fixation device 60.

[0115] Step 4 (

[35] ): Remove the handle 62 from the bone cement fixation device 60 and remove the removed internal fixation device 10 and screwdriver 20.

[0116] Step 5 (

[36] ): The bone cement fixation device 60 is removed and the incised skin 94 is sutured to complete the treatment. If the tip 61 of the bone cement fixation device 60 is firmly embedded in the hole 2 of the bone cement 1, the handle 62 is attached and it is removed. However, if it is simply stuck, the bone cement fixation device 60, the internal fixation device 10, and the driver 20 may be removed together at the same time, rather than removing the internal fixation device 10 and the driver 20 in Step 4 (

[35] ).

[0117] Steps 3 (

[34] ) and 4 (

[35] ) are the same as steps 4 (

[25] ) and 5 (

[26] ) in the example shown in Figure 13. Since the bone cement fixation device 60 is inserted directly into the internal fixation device 10 to be removed in step 1 without using the guide pin 40, the number of steps can be reduced.

[0118] This procedure was described assuming that the tip of the internal fixation device 10 has screw threads or grooves, and that insertion and removal from the bone cement 1 are performed by rotating the screw in and out. However, this procedure can also be applied if the tip of the internal fixation device 10 does not have screw threads or the like, and insertion and removal of the internal fixation device 10 from the bone cement 1 are performed by simple pushing and pulling. In that case, the bone cement fixation device 60 will suppress movement in the same pulling direction as the internal fixation device 10 is pulled out, rather than suppressing the rotational movement of the bone cement 1.

[0119] [Embodiment 2] In Embodiment 1, the solution principle was to pre-form a hole 2 of a predetermined shape in the bone cement 1 using the tip 51 of the bone cement molding instrument 50, and then to suppress the rotation of the bone cement 1 by fitting the tip 61 of the bone cement fixing instrument 60, which had the same shape. However, the tip 61 of the bone cement fixing instrument 60 does not necessarily have to be the same shape as the tip 51 of the bone cement molding instrument 50; it is sufficient that it fits into the hole 2 formed using the tip 51 of the bone cement molding instrument 50 and suppresses the rotation of the bone cement 1.

[0120] Figure 15 is an explanatory diagram showing the tip portions of a bone cement molding instrument 50 and a bone cement fixation instrument 60, which are examples of treatment instruments of the second embodiment of the present invention, and shows the bottom surface as viewed from the proximal end side (bottom side). (a) is the tip portion 51 of the bone cement molding instrument 50. It has the same shape as the bone cement molding instrument 50 of Embodiment 1 shown in Figure 3, and has a cylindrical shaft and a rectangular prism tip portion 51, while the bone cement fixation instrument 60 has a cylindrical shaft and a rectangular prism tip portion 61. The diameter d50 of the cylindrical shaft of the bone cement molding instrument 50 is slightly smaller than the diameter d10 of the through hole 16 of the bone cement 10, and the rectangular prism of the tip portion 51 is formed inside it. For example, the length d51 of the diagonal of the square in the cross-section of the regular rectangular prism is equal to or smaller than d50.

[0121] (b) is the tip 61 of the bone cement fixation device 60. The bone cement fixation device 60 has a cylindrical shaft and a columnar tip 61 with a cross-shaped cross section. The diameter d60 of the cylindrical shaft of the bone cement fixation device 60 is slightly smaller than the diameter d10 of the through hole 16 of the bone cement 10, and the tip 61 is formed inside it. For example, the width d61 of the cross-shaped cross section is preferably equal to or smaller than d51, and is sized to fit roughly snugly into the hole 2 formed by the tip 51 of the bone cement molding device 50. It is sufficient that it fits snugly and prevents the bone cement 1 from rotating, so it does not need to fit snugly and some clearance is acceptable.

[0122] Figure 15 illustrates the example using a rectangular prism and a cross shape, but a straight line shape that fits into the diagonal of the rectangular prism is also acceptable. There are many other variations, such as making the tip 51 of the bone cement molding instrument 50 a hexagonal prism and the tip 61 of the bone cement fixing instrument 60 a triangular prism, or making the tip of the cross tapered.

[0123] [Embodiment 3] Let me explain a further variation. This is the case where the tip 51 of the bone cement molding instrument 50 is cylindrical. For example, when the internal fixation device 10 is implanted in the vertebral body, there may be cases where a special bone cement molding instrument 50 is not available, and a guide pin, a cylindrical bone cement injector, or a cement pusher is used as a substitute to form the hole 2. Since the hole 2 is circular, there is no option for the shape of the tip 61 of the bone cement fixation device 60 that would allow the rotation of the bone cement 1 to be prevented simply by fitting it in.

[0124] Figure 16 is an explanatory diagram showing an overview of the tip portions of a bone cement molding instrument 50 and a bone cement fixation instrument 60, which are examples of treatment instruments according to the third embodiment of the present invention. The tip portion 51 of the bone cement molding instrument 50 is cylindrical, as shown in Figure 16(a). The tip portion 61 of the bone cement fixation instrument 60 has a screw thread that is tapped into the hole 2 formed by the tip portion 51 of the bone cement molding instrument 50, and a blunt tip that contacts the bottom of the hole 2 and stops insertion, as shown in Figure 16(b). More specifically, the outer circumference of the cylindrical portion of the tip portion 61 of the bone cement fixation instrument 60 is smaller than the diameter of the hole 2, and the diameter of the outer circumference tracing the apex of the tapping screw thread is equal to or larger than the diameter of the hole 2. Theoretically, this diameter needs to be larger than the diameter of hole 2 for tapping. However, in reality, the bone cement 1 may not have hardened sufficiently when hole 2 is formed, and it cannot be said that there is absolutely no possibility that hole 2 will become smaller after the bone cement forming instrument 50 is removed. Therefore, it should be considered that the outer diameter of the tapping thread at the tip 61 of the bone cement fixing instrument 60 be equal to the diameter of hole 2.

[0125] This makes it possible to provide another bone cement fixing device 60 that can suppress the rotation of the bone cement 1. For example, as an example of a bone cement molding device 50, a hole 2 is formed in the bone cement 1 using a guide pin 40 or a bone cement injector 80, and the tip 61 of the bone cement fixing device 60 is equipped with a tapping screw thread that is equal to or larger in outer diameter than the thickness of the guide pin 40, so that the bone cement fixing device 60 is screwed in to fix the bone cement 1, and the internal fixing device 10 can be rotated in the reverse direction by operating the screwdriver 20 and removed.

[0126] Figure 17 is an explanatory diagram showing the external appearance and cross-sectional structure of the tip of the bone cement molding instrument 50 and the bone cement fixing instrument 60, in order to illustrate another configuration example of the bone cement molding instrument 50 and the bone cement fixing instrument 60. While the tip 51 of the bone cement molding instrument 50 and the tip 61 of the bone cement fixing instrument 60 shown in Figure 16 are cylindrical, in the example shown in Figure 17, the tip 51 of the bone cement molding instrument 50 and the tip 61 of the bone cement fixing instrument 60 are cylindrical tapered. A cylindrical tapered shape is a shape in which the diameter of the cylinder becomes smaller towards the tip, and as shown, it may be a frustocone or a cone. The outer circumferential surface of the tip 51 of the bone cement molding instrument 50 is smooth, and the outer circumferential surface of the tip 61 of the bone cement fixing instrument 60 has tapping threads formed thereon. As shown in (c), the hole 2 formed by the tip 51 of the bone cement molding instrument 50 narrows towards the bottom, so the tapping threads formed on the outer circumference of the tip 61 of the bone cement fixing instrument 60 are screwed into the side wall of the hole 2, and the tip 61 of the bone cement fixing instrument 60 fits into the hole 2 and stops before the tip of the tip 61 reaches the bottom of the hole 2. The bone cement fixing instrument 60 can suppress rotational and pull-out forces on the bone cement 1.

[0127] In Figure 17, the diameters of the bottom surfaces (the sides that contact the shaft) of the tip 51 of the bone cement molding instrument 50 and the tip 61 of the bone cement fixing instrument 60 are depicted as smaller than the diameter of the shaft, but they may be the same diameter as the shaft. However, the outer diameter of the screw threads formed on the tip 61 of the bone cement fixing instrument 60 must be smaller than the diameter of the through hole 16 of the internal fixing instrument 10.

[0128] Figure 18 is a schematic diagram illustrating an example of the procedure for removing the internal fixation device 10 during treatment using the treatment device of the third embodiment.

[0129] Initial state (

[41] ): The patient's vertebral body 90 is internally fixed by bone cement 1 being supported by an internal fixation device 10 inserted from the pedicle 91. A hole 2 is formed in the bone cement 1 through a through hole 16 of the internal fixation device 10. In Figure 18, the hole 2 is assumed to be a cylindrical hole formed from a cylinder, but as mentioned above, the same applies if it is a tapered cylinder (frustum of a cone or cone) instead of a cylinder.

[0130] Step 1 (

[42] ): The subcutaneous tissue from the skin 94, which is the surface of the patient's back, to the affected vertebral body 90 is incised and perforated, and the guide pin 40 is introduced into the through-hole 16 of the internal fixation device 10 inserted into the pedicle 91. Figure 18

[42] illustrates how the guide pin 40 has been introduced up to the hole 2 formed in the bone cement 1 inside the vertebral body 90, but it is sufficient if it has reached the through-hole 16 of the internal fixation device 10.

[0131] Step 2 (

[43] ): Guide the screwdriver 20 to the internal fixing device 10 by aligning the through-hole of the screwdriver 20 with the inserted guide pin 40, and connect the tip of the screwdriver 20 by fitting it into the head (connecting part) 13 of the internal fixing device 10.

[0132] Step 3 (

[44] ): The bone cement fixation device 60 is inserted into the through-hole 16 of the internal fixation device 10 and the through-hole 20 of the internal fixation device 10, which are connected by the connection between the driver 20 and the internal fixation device 10, and guided into the vertebral body 90, with the tip 61 inserted into the hole 2 of the bone cement 1. The tip 61 of the bone cement fixation device 60 is provided with a tapping screw thread, so it is advanced while tapping the hole 2 of the bone cement 1, and stops when the tip of the tip 61 reaches the bottom of the hole 2. After that, tapping is advanced while holding the driver 20 to prevent the bone cement 1 from rotating. The tapping creates a force that pulls out the internal fixation device 10 in a direction opposite to the rotational force of the bone cement 1, creating a gap between the internal fixation device 10 and the bone cement 1, allowing it to be removed.

[0133] Step 4 (

[45] ): With the tip 61 of the bone cement fixation device 60 fitted into the hole 2 of the bone cement 1 and rotation suppressed, the internal fixation device 10 is removed by rotating the screwdriver 20 while holding the bone cement fixation device 60 with the handle 62 to prevent it from rotating. If the screw threads 15 on the distal side of the internal fixation device 10 tapped the pedicle 91 during insertion, rotating it in the opposite direction to the insertion direction can provide a thrust force to remove the internal fixation device 10, allowing it to be removed smoothly. For example, if the bone cement fixation device 60 is advanced towards the bottom of the hole 2 and rotated clockwise, the internal fixation device 10 can be removed by rotating the screwdriver 20 counterclockwise while maintaining that clockwise force. Even if the bone cement 1 tries to rotate counterclockwise due to the force of rotating the screwdriver 20 counterclockwise, the rotation of the bone cement 1 can be suppressed by the force of rotating the bone cement fixation device 60 clockwise.

[0134] Step 5 (

[46] ): The bone cement fixation device 60 is removed, and the incised skin 94 is sutured to complete the treatment. The tip 61 of the bone cement fixation device 60 can be removed by rotating it in the opposite direction to the direction of insertion. At this time, it is not possible to apply force to prevent the rotation of the bone cement 1, but since the insertion of the bone cement fixation device 60 is a tapping of the bone cement 1 that has hardened completely after a long period of time, it can be removed with a weak force without rotating the bone cement 1. Furthermore, by immediately loosening the bone cement fixation device 60 when the connection of the internal fixation device 10 to the bone cement 1 has loosened slightly, it is possible to prevent the bone cement fixation device 60 from becoming too tightly stuck and becoming impossible to remove.

[0135] If the bone cement 1 were to easily rotate away from the surrounding tissue, this could be resolved by using two types of bone cement fixation devices 60: one with a tip 61 having a relatively large outer diameter thread for forming a tapping groove, and another with a smaller outer diameter thread. The bone cement fixation device 60 with the large outer diameter thread is used to form a tapping groove, and then the bone cement fixation device 60 with the smaller outer diameter thread is inserted along the formed tapping groove to the bottom of the hole 2. The bone cement fixation device 60 with the smaller outer diameter thread is used to prevent the bone cement 1 from rotating when the internal fixation device 10 is removed. Since this bone cement fixation device 60 has a smaller outer diameter thread and is simply inserted along the pre-formed tapping groove, it can be pulled out with little force by rotating it in the reverse direction.

[0136] Figure 19 is a schematic diagram illustrating another example of the procedure for removing the internal fixation device 10 during treatment using the therapeutic device of this third embodiment.

[0137] Initial state (

[51] ): As in

[41] in Figure 18, the patient's vertebral body 90 is internally fixed by bone cement 1 being supported by an internal fixation device 10 inserted from the pedicle 91. A hole 2 is formed in the bone cement 1 through the through hole 16 of the internal fixation device 10. In Figure 19, the hole 2 is assumed to be a cylindrical hole formed from a cylinder, but the same can be said if it is a tapered cylinder instead of a cylinder.

[0138] Step 1 (

[52] ): An incision and perforation are made in the subcutaneous tissue from the skin 94, which is the surface of the patient's back, to the affected vertebral body 90, and a bone cement fixation device 60 is inserted into the through-hole 16 of the internal fixation device 10 inserted into the pedicle 91, in place of the guide pin 40

[42] in Figure 18. With the handle 62 removed from the bone cement fixation device 60, the bone cement fixation device 60 is first inserted into the through-hole 16 of the internal fixation device 10, or a screwdriver 20 may be inserted in advance from the tip side of the bone cement fixation device 60 with the handle 62 attached, and the tip 61 of the bone cement fixation device 60 is inserted into the through-hole 16 of the internal fixation device 10 while holding it in place with a hand.

[0139] Step 2 (

[53] ): Attach the handle 62 to the bone cement fixation device 60 and screw the tip 61 into the hole 2. Guide the screwdriver 20 along the bone cement fixation device 60 into which the through-hole of the screwdriver 20 has been inserted, and guide the screwdriver 20 to the internal fixation device 10. Fit the tip of the screwdriver 20 into the head (connecting part) 13 of the internal fixation device 10 to connect them. Screwing the tip 61 of the bone cement fixation device 60 into the hole 2 may be done after connecting the screwdriver 20 and the internal fixation device 10.

[0140] Step 3 (

[54] ): With the tip 61 of the bone cement fixation device 60 fitted into the hole 2 of the bone cement 1 and rotation suppressed, the internal fixation device 10 is removed by rotating the screwdriver 20 while holding the bone cement fixation device 60 with the handle 62 to prevent it from rotating. If the screw threads 15 on the distal side of the internal fixation device 10 tapped the pedicle 91 during insertion, rotating it in the opposite direction to the insertion direction can provide a thrust force to remove the internal fixation device 10, allowing it to be removed smoothly. For example, if the bone cement fixation device 60 is advanced towards the bottom of the hole 2 and rotated clockwise, the internal fixation device 10 can be removed by rotating the screwdriver 20 counterclockwise while maintaining that clockwise force. Even if the bone cement 1 tries to rotate counterclockwise due to the force of rotating the screwdriver 20 counterclockwise, the rotation of the bone cement 1 can be suppressed by the force of rotating the bone cement fixation device 60 clockwise.

[0141] Step 4 (

[55] ): The bone cement fixation device 60 is removed, and the incised skin 94 is sutured to complete the treatment.

[0142] As described above, by using the bone cement fixation device 60 in place of the guide pin 40 in Figure 18, the removal procedure can be simplified. In this case, it is preferable to configure the bone cement fixation device 60 so that a handle 62 can be attached to and detached from it.

[0143] [Embodiment 4] Figure 20 is a schematic explanatory diagram showing examples of the configuration of a bone cement molding instrument 50 and a driver 20 according to the fourth and fifth embodiments of the present invention.

[0144] The fourth embodiment is a modification of the third embodiment described with reference to Figure 16, and not only the bone cement fixing device 60 but also the bone cement molding device 50 has screw threads that tap into the side wall of the hole 2 and screw into it. This makes it possible to pre-tap grooves into the side wall of the hole 2. When it becomes necessary to remove the internal fixing device 10, the tapping screw threads of the bone cement fixing device 60 are screwed into the grooves that have been pre-formed in the hole 2, so it can be screwed in and removed with little force, and it also becomes easy to remove the bone cement fixing device after the internal fixing device has been removed.

[0145] Figure 20 is drawn in combination with the fifth embodiment described later, but it is not necessarily required to implement them in combination.

[0146] [Embodiment 5] In the treatment instrument 100 of Embodiment 5, the bone cement molding instrument 50 may be inserted into a through-hole of a driver 20 connected to the internal fixation device 10, and configured to protrude a predetermined length (for example, about 1 cm) from the tip of the internal fixation device 10, as illustrated in Figure 20. This allows the bone cement molding instrument 50 to be inserted and the hole 2 formed while the driver 20 and the internal fixation device 10 are connected, and the number of steps in the procedure can be reduced, as will be described later.

[0147] In this case, it is even more preferable that the bone cement molding instrument 50 be configured to be detachable from the driver 20. This is because it allows for selective use of either simultaneously or separately, the molding of the hole 2 and the insertion of the internal fixation device 10 into the bone cement 1.

[0148] The bone cement molding instrument 50 and the screwdriver 20 can be configured to be integrated by screwing them together, for example, by providing a screw structure on the distal end of each. Other connection methods are also acceptable. For example, a connector structure that does not come off unless pulled strongly may be used, or a latch structure that holds the connection may be used. This improves the operability of the treatment instrument 100 when the molding of the hole 2 and the insertion of the internal fixation device 10 into the bone cement 1 are performed simultaneously. As shown in the diagram, the handle 27 of the screwdriver 20 and the handle 52 of the bone cement molding instrument 50 can be integrated, making it easier to grip with one hand.

[0149] Figure 21 is a schematic diagram illustrating the latter half of the procedure for implanting the internal fixation device 10 in treatment using the treatment device 100 of the fifth embodiment. The first half of the procedure for implanting the internal fixation device 10 is the same as the first step ([1]) to the sixth step ([6]) explained with reference to Figure 10, so the explanation is omitted. Similar to Figures 10 and 11, Figure 21 schematically shows a cross-section of the affected area of ​​the patient, with the upper side of the paper being distal and the lower side being proximal, from the outside of the skin 94 through the pedicle 91 to the vertebral body 90. The scale in the central axis direction (vertical direction of the paper) has been compressed, and the direction along the patient's body surface (horizontal direction of the paper) has been emphasized. Since there are pedicles 91 on both the left and right sides of the vertebral body 90, the same procedure is performed on one vertebral body 90 from both sides, but Figure 21 shows one of them.

[0150] Step 7 (

[67] ): Withdraw the balloon catheter 70 from the driver 20 and the through-hole of the internal fixation device 10, insert the cement injector 80, and inject bone cement 1 into the vertebral body 90.

[0151] Step 8 (

[68] ): The cement injector 80 is withdrawn from the through-holes of the driver 20 and the internal fixing device 10, and the bone cement molding instrument 50 is inserted through the through-hole of the driver 20, with its tip 51 protruding into the bone cement 10 from the tip of the internal fixing device 10. At this time, Figure 21 is drawn assuming the bone cement molding instrument 50 illustrated in Figure 20, but is not limited to this embodiment of the bone cement molding instrument 50, and the tip 51 may be cylindrical, cylindrical tapered (frustocone or cone), for example, and the presence or absence of tapping threads on the outer surface is also optional.

[0152] Step 9 (

[69] ): Using the screwdriver 20, the internal fixation device 10 is screwed into the filled bone cement 1, and at the same time, the bone cement molding instrument 50 is also inserted into the bone cement 1, forming the hole 2. It is preferable, however, that the bone cement molding instrument 50 is integrated with the screwdriver 20 by a screw structure at its distal end, as illustrated in Figure 21.

[0153] Step 10 (

[70] ): Remove the driver 20 and suture the incised skin 94 to complete the treatment.

[0154] As described above, compared to the procedure explained with reference to Figure 11, the procedure can be shortened because the insertion of the internal fixation device 10 and the shaping of the hole 2 with the bone cement molding device 50 can be performed simultaneously.

[0155] [Embodiment 6] In the first to fifth embodiments described above, the bone cement fixation device 60 may be provided with a through hole through which a guide pin can pass. This allows the bone cement fixation device 60 to be guided into the hole 2 in the bone cement 1 of the affected area by following the guide pin 40 that has been inserted into the affected area in advance.

[0156] Figure 22 is a schematic diagram illustrating an example of the procedure for removing the internal fixation device 10 during treatment using the treatment device of the sixth embodiment of the present invention.

[0157] Initial state (

[71] ): The patient's vertebral body 90 is internally fixed by bone cement 1 being supported by an internal fixation device 10 inserted from the pedicle 91. A hole 2 of a predetermined shape is formed in the bone cement 1 through a through hole 16 of the internal fixation device 10.

[0158] Step 1 (

[72] ): The subcutaneous tissue from the skin 94, which is the surface of the patient's back, to the affected vertebral body 90 is incised and perforated, and a guide pin 40 is inserted into the through-hole 16 of the internal fixation device 10 inserted into the pedicle 91, and its tip is guided to reach the hole 2 formed in the bone cement 1 inside the vertebral body 90.

[0159] Step 2 (

[73] ): Guide the bone cement fixation device 60, together with the screwdriver 20, towards the hole 2 formed in the bone cement 1 by aligning it with the guide pin 40.

[0160] Step 3 (

[74] ): Insert the bone cement fixation device 60 into hole 2, connect the screwdriver 20 to the internal fixation device 10 with its head 13, and remove the guide pin 40.

[0161] Step 4 (

[75] ): With the tip 61 of the bone cement fixation device 60 fitted into the hole 2 in the bone cement 1 and its movement in the direction of rotation and / or withdrawal suppressed, the internal fixation device 10 is removed by rotating the screwdriver 20 while holding the bone cement fixation device 60 with the handle 62 to prevent it from rotating and being withdrawn. As with the other embodiments described above, if the screw threads 15 provided on the distal side of the internal fixation device 10 tapped the pedicle 91 during insertion, rotating it in the opposite direction to the insertion direction can provide a thrust force to the internal fixation device 10 in the direction of withdrawal, allowing the internal fixation device 10 to be removed smoothly. Alternatively, if the internal fixation device 10 does not have a structure such as screw threads, it is also possible to tap and remove the internal fixation device 10 using the screwdriver 20 or an instrument such as forceps to grasp the internal fixation device 10 while suppressing its movement in the direction of withdrawal of the bone cement 1 with the bone cement fixation device 60.

[0162] Step 5 (

[76] ): The bone cement fixation device 60 is removed, and the incised skin 94 is sutured to complete the treatment.

[0163] As described above, by providing the bone cement fixation device 60 with a through-hole through which a guide pin can pass, the bone cement fixation device 60 can be easily and accurately guided into the hole 2 formed by the bone cement molding device 50, thereby allowing the procedure for removing the internal fixation device 10 to proceed smoothly.

[0164] Although the present inventors have described the invention in detail based on embodiments above, it goes without saying that the present invention is not limited thereto and can be modified in various ways without departing from its essence. [Industrial applicability]

[0165] The present invention relates to a cylindrical internal fixation device for medical use, and is particularly suitable for use in internal fixation surgery of the vertebral body, which is the affected area. [Explanation of Symbols]

[0166] 1. Bone cement 2 holes 10 internal fixation devices 12 shafts 13. Head (connection point to the driver) 14 groove 15 screw threads 16 Through holes 17 Slope 20 Drivers 25 Connection part with inner cylinder 26 Male screw 27 Driver handle 30 Inner cylinder 31. Inner tube tongue 32 Tip of the inner cylinder 33 Notches 34 Threads at the tip of the inner cylinder 35. Connection point to the driver 36 Female thread 37. Handle of the inner cylinder 40 guide pins 50 Bone cement molding instruments 51 Tip of bone cement molding instrument 52 handle 53 Connecting part 54 Screw threads 60 Bone cement fixation devices 61 Tip of bone cement fixation device 62 handle 64 Through holes 70 Balloon catheter 71 Balloons 80 Cement Injector 90 vertebral bodies 91 vertebral pedicle 92 vertebral arch 93 Spinal canal 94 Skin 100 Treatment Equipment

Claims

1. A therapeutic device comprising a bone cement molding device and a bone cement fixing device, which are inserted into an internal fixation device to support the bone cement from the pedicle by integrating with the bone cement filled inside the vertebral body, The internal fixation device has a through-hole in the central axis direction from the head to the tip, is inserted into the vertebral body from the pedicle, and integrates with the bone cement as the surrounding bone cement hardens and fixes in place. The bone cement molding instrument has a tip shape that allows it to be inserted into the bone cement through the through-hole of the internal fixing instrument before the bone cement hardens, thereby forming a hole of a predetermined shape. The bone cement fixation device has a tip portion that is inserted into the hole, and the tip portion has a tip shape that, after the bone cement has hardened, can suppress the rotation of the bone cement around its central axis caused by the rotation of the internal fixation device in order to release it from the bone cement and remove it, by inserting the tip portion into the hole through the through-hole of the internal fixation device. treatment equipment.

2. In claim 1, The bone cement fixation device has a screw thread that taps into the side wall of the hole and is screwed in. treatment equipment.

3. A therapeutic device comprising a bone cement molding device and a bone cement fixing device, which are inserted into an internal fixation device for supporting the bone cement from the pedicle by becoming integrated with the bone cement filled inside the vertebral body, The internal fixation device has a through-hole in the central axis direction from the head to the tip, is inserted into the vertebral body from the pedicle, and integrates with the bone cement as the surrounding bone cement hardens and fixes in place. The bone cement molding instrument has a tip shape that allows it to be inserted into the bone cement through the through-hole of the internal fixing instrument before the bone cement hardens, thereby forming a hole of a predetermined shape. The bone cement fixation device has a tip portion that is inserted into the hole, and the tip portion has a tip shape that, after the bone cement has hardened, can be inserted into the hole through the through-hole of the internal fixation device, thereby suppressing the rotation and / or movement of the bone cement around the central axis and / or in the pulling direction caused by the rotation and / or pulling operation for releasing and removing the internal fixation device from the bone cement. The aforementioned treatment device further includes a screwdriver, The aforementioned internal fixing device is connectable to a driver at the head, The driver, when connected to the internal fixing device, has a through-hole that communicates with the through-hole of the internal fixing device and allows the respective tip portions of the bone cement molding device and the bone cement fixing device to pass through. treatment equipment.

4. In claim 3, The bone cement molding device is inserted into the through-hole of the screwdriver connected to the internal fixation device, and protrudes a predetermined length from the tip of the internal fixation device. treatment equipment.

5. In claim 4, The bone cement molding device is detachably connected to the driver. treatment equipment.

6. In claim 5, The driver has a screw structure at its distal end that can be connected to the bone cement molding device. treatment equipment.

7. In claim 1, the bone cement fixation device has a structure in which the handle portion and the shaft portion are detachable. treatment equipment.

8. In claim 1 or claim 3, The tip of the bone cement molding instrument has a circular cross-section with a diameter that is constant or decreases towards the tip. The bone cement fixation device has a screw thread that taps into the side wall of the hole and is screwed in. treatment equipment.

9. In claim 1, The treatment device further includes a guide pin, and the bone cement fixation device has a through hole through which the guide pin can pass. treatment equipment.

10. In claim 1, The tip of the bone cement molding instrument is prismatic in shape or prismatic tapered in shape, with the cross-section becoming smaller towards the tip. The bone cement fixing device has a tip shape that can contact the side wall of the hole to suppress the rotation of the bone cement. treatment equipment.

11. In claim 10, the bone cement fixation device has a structure in which the handle portion and the shaft portion are detachable. treatment equipment.

12. In claim 10, The aforementioned treatment device further includes a screwdriver, The aforementioned internal fixing device is connectable to a driver at the head, The driver, when connected to the internal fixing device, has a through-hole that communicates with the through-hole of the internal fixing device and allows the bone cement molding device and the tip portion of the bone cement fixing device to pass through. treatment equipment.

13. In any one of claims 10 to 12, The treatment device further includes a guide pin, and the bone cement fixation device has a through hole through which the guide pin can pass. Treatment equipment.

Images