Radial Plate Fixation Screw Tool

Abstract

The present invention is provided with: a rotational force input unit 11; a rotation shaft 12 which extends in the axial direction from the distal end of the rotational force input unit and can relatively rotate; an intermediate cylinder 13 in which a screw connection portion 12c at the distal end of the rotation shaft protrudes from the distal end and which is disposed outside the rotation shaft to be movable in the axial direction between a rotation position A and an idle rotation position B, and has a first fitting protrusion 13c on the outer circumferential surface; and an outer cylinder 14 disposed outside the intermediate cylinder to be relatively movable in the axial direction and having, on the inner circumferential surface, a second fitting protrusion 14c which, when the intermediate cylinder is positioned at the rotation position, fits to the first fitting protrusion around the axis and can rotate together with the intermediate cylinder, and when the intermediate cylinder is positioned at the idle rotation position, is released from the fitting with the first fitting protrusion around the axis and can rotate relative to the intermediate cylinder.

Description

[Technical field]

[0001] The present invention relates to a tool for a radial fixation plate fixation screw, which rotates a fixation screw when fixing a radial fixation plate to a radius. [Background technology]

[0002] When the radius is fractured, a radial fixation plate that spans the fractured portion to fix the radius is known as an alternative to a splint (i.e., a splint) or a plaster or FRP cast in order to fix the fractured portion of the radius.

[0003] When the radial fixation plate is fixed to the radius, a plurality of fixation screws are screwed into the radius to fix the plate to the radius.

[0004] Conventionally, a radial fixation plate has been made of a metal plate such as titanium or an alloy thereof, which is strong, lightweight, and highly biosafe.

[0005] However, metal plates cannot be penetrated by X-rays, making it difficult to grasp the condition of the fractured area covered by the radial fixation plate.

[0006] Therefore, in recent years, instead of metal plates, resin radius fixation plates have been developed (for example, see Patent Document 1). When such a resin radius fixation plate is fixed to the radius with a screw, if the fixation screw is screwed into the radius too far, the radius fixation plate may crack and break, or the fixation screw may penetrate the radius fixation plate. Therefore, it is necessary to restrict the screw tightening depth and excessive rotation so that the fixation screw is not screwed into the radius too far.

[0007] When using metal plates, a commercially available torque limiter can be used to control the torque and thereby regulate the screw tightening depth.

[0008] [Patent Document 1] JP 2016-16168 A DISCLOSURE OF THEINVENTION

[0009] However, even when such commercially available torque limiters are used, there are problems such as the following. For example, in the case of a conventional metal radius fixation plate, if the fixation screw is tightened excessively beyond the required torque, the metal radius fixation plate can withstand that torque. However, in the case of a plastic radius fixation plate, if the fixation screw is tightened excessively beyond the required torque, the plastic radius fixation plate cannot withstand that torque and may be damaged or penetrated. Thus, the conventional torque limiter cannot regulate the tightening depth and rotation of the screw.

[0010] Therefore, the object of the present invention is to solve the above-mentioned problems and to provide a tool for radial fixation plate fixation screws that can easily and reliably regulate the tightening depth and rotation of the fixation screws of a resin radial fixation plate.

[0011] In order to achieve the above object, the present invention is configured as follows.

[0012] According to a first aspect of the present invention, there is provided a radial fixation plate fixation screw tool for rotating a fixation screw that fixes a radial fixation plate to a radius, comprising: a rotational force input unit to which a rotational force for rotating the fixing screw is input; a rotation shaft portion extending in an axial direction from a tip end of the rotational force input portion and rotatable relatively to the rotational force input portion; a center cylinder having a screw coupling portion at a tip end of the rotating shaft portion protruding from the tip end, the center cylinder being disposed outside the rotating shaft portion so as to be movable in the axial direction between a rotating position and an idling position, and the center cylinder having a first engagement projection on its outer circumferential surface; The second engagement protrusion is disposed on the inner circumferential surface of the inner cylinder so as to be relatively movable in the axial direction, and is engaged with the first engagement protrusion around the axis and is rotatable integrally with the inner cylinder when the inner cylinder is located at the rotation position, while being disengaged from the first engagement protrusion around the axis and is rotatable relative to the inner cylinder when the inner cylinder is located at the idling position. and a rotational force input unit which is rotatable integrally with the rotational force input unit. An outer cylinder, A radial fixation plate locking screw tool is provided, comprising: According to a second aspect of the present invention, there is provided a radial fixation plate fixation screw tool for rotating a fixation screw that fixes a radial fixation plate to a radius, comprising: a rotational force input unit to which a rotational force for rotating the fixing screw is input; a rotating shaft portion extending in an axial direction from a tip of the rotational force input portion, being rotatable integrally with the rotational force input portion, the rotating shaft portion having a screw coupling portion at a tip and a first engagement portion on a base end side; The rotary shaft portion is inserted to be relatively rotatable and relatively movable in the axial direction, and the tip is capable of contacting a guide tube regulating portion of a screw insertion hole of the radial fixation plate or a screw insertion hole of a screw guide block placed on the radial fixation plate, and the base end is engaged with the first engagement portion. do A guide tube having a second engagement portion and being a separate member from the rotating shaft portion; Equipped Along with, The screw guide block is placed on the radial fixation plate, and a second rotation stopper is provided on the outer periphery of the guide tube, the second rotation stopper being engageable with a first rotation stopper of the screw insertion hole of the screw guide block. A third engagement portion is provided on a base end side of the rotating shaft portion, A fourth engagement portion is provided on a base end side of the guide tube, the fourth engagement portion being adapted to contact and engage with the third engagement portion and to restrict movement of the rotation shaft portion in a screw-in direction, The first engaging portion and the second engaging portion engage with each other, and the third engaging portion and the fourth engaging portion come into contact with each other and engage with each other, thereby restricting the relative rotation between the guide tube and the rotating shaft portion and restricting the movement of the rotating shaft portion in the screwing direction. A tool for radial fixation plate fixation screws is provided.

[0013] According to the first aspect of the present invention, when the first engaging projection and the second engaging projection are engaged with each other, the torque generated when the torque input unit is rotated is transmitted to the rotating shaft unit through the outer tube and the middle tube, and the fixing screw engaged with the rotating shaft unit is rotated in the tightening direction. On the other hand, when the fixing screw is screwed into the radius and the tightening depth of the fixing screw reaches a dimension to be regulated, the middle tube comes into contact with the radius fixation plate or the guide block arranged on the radius fixation plate, and the middle tube is moved back toward the torque input unit side relative to the shaft unit, and the engagement around the axis between the first engaging projection and the second engaging projection is released. Then, even if the torque input unit is rotated to rotate the outer tube, the outer tube and the middle tube rotate idly, and the torque from the outer tube is not transmitted to the shaft unit, and the rotation is regulated. At the same time, the fixing screw is not screwed in beyond the dimension, and the depth (i.e., the tightening depth of the screw) can also be regulated. Therefore, the tightening depth and rotation of the fixing screw of the resin radius fixation plate can be easily and reliably regulated. According to the second aspect of the present invention, when the rotational force input part is rotated relative to the guide tube arranged in the screw insertion hole of the radius fixation plate or the guide block, the rotation shaft part rotates and the first engagement part engages with the second engagement part, so that the rotation shaft part cannot rotate any further and the fixing screw cannot be screwed into the radius together with the rotation shaft part, thereby restricting the depth (i.e., the screw fastening depth) and the rotation. Therefore, the fastening depth and rotation of the fixing screw of the resin radius fixation plate can be easily and reliably restricted. [Brief description of the drawings]

[0014] These and other objects and features of the present invention will become apparent from the following description of the preferred embodiment taken in conjunction with the accompanying drawings, in which: [Figure 1] FIG. 1 is a perspective view showing a state in which a radial fixation plate is fixed to a radius by a fixing screw using a tool for fixing a radial fixation plate to a radius according to a first embodiment of the present invention; [Diagram 2] A perspective view of a guide block to be placed on a radial fixation plate. [Diagram 3] Side view of the guide block in Figure 2 [Figure 4]FIG. 1 is a partially perspective explanatory view showing a state in which a fixing screw is inserted through a guide block and a radial fixation plate by a tool for fixing screws of a radial fixation plate according to a first embodiment of the present invention and fastening is started; [Diagram 5] FIG. 1 is a partially perspective explanatory diagram showing the state where the fixation screw is nearly completed when the fixation screw is inserted through the guide block and the radial fixation plate using a tool for fixing the radial fixation plate screws. [Figure 6] FIG. 1 is a partially perspective explanatory diagram showing the state in which the center cylinder is in contact with the guide block and in the idling position when the fixing screw is inserted through the guide block and the radial fixation plate by the radial fixation plate fixing screw tool and tightened. [Figure 7] Side view of radial plate locking screw tool [Figure 8] A longitudinal section taken along line VIII-VII in Figure 7. [Figure 9] Cross-sectional view taken along line XI-XI in Figure 7. [Figure 10] A perspective view of a rotating shaft of a tool [Figure 11] Side view of the tool barrel [Figure 12] A perspective view of the tool's cylinder [Figure 13] Right side view of the tool's center cylinder [Figure 14] A perspective view of the outer cylinder of the tool [Figure 15] Longitudinal cross section of the tool's outer cylinder [Figure 16A] FIG. 13 is a schematic explanatory view, partially in perspective, of a state in which the center cylinder is in contact with the radial fixation plate and is positioned at an idling position to complete fastening when the fastening screw is inserted through the radial fixation plate by the tool for fastening the radial fixation plate screws according to the modified example of the first embodiment of the present invention; [Figure 16B] FIG. 16B is a perspective view of an example of a radial bone fixation plate for explaining the state of FIG. 16A; [Figure 16C] FIG. 16B is a partially enlarged perspective view of the [Figure 16D] A longitudinal cross-sectional view of the screw insertion hole in Figure 16B [Figure 17] FIG. 13 is a perspective view of a main body of a tool for fixing a radial bone plate screw according to a second embodiment of the present invention; [Figure 18]FIG. 13 is a perspective view of a guide tube of a tool for fixing a radial bone plate screw according to a second embodiment of the present invention; [Figure 19A] FIG. 19 is a vertical cross-sectional view of the guide tube of FIG. [Figure 19B] FIG. 18 is a left side view of the guide tube. [Figure 20] FIG. 1 is a perspective view of a state in which the fixation screw is inserted through the guide block and the radial fixation plate by the radial fixation plate fixation screw tool and then tightened; [Figure 21] FIG. 1 is a longitudinal sectional view showing a state in which a fixation screw is inserted through a guide block and a radial fixation plate by a radial fixation plate fixation screw tool and tightened; [Figure 22] FIG. 1 is a longitudinal cross-sectional view showing a state in which a fixing screw is inserted through a guide block and a radial fixation plate using a radial fixation plate fixing screw tool and then tightened. [Figure 23] A longitudinal cross-sectional view showing the state in which the fixation screw is inserted into the radial fixation plate using a radial fixation plate fixation screw tool without a guide block and tightened. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Before continuing with the description of the present invention, reference is made to the accompanying drawings in which like parts are designated by like reference numerals. Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.

[0016] As shown in Fig. 1, the tool 1 for fixing a radius fixation plate 2 to a radius 3 according to the first embodiment of the present invention is a tool for rotating a fixing screw 4 for fixing a radius fixation plate 2 to a radius 3. When fixing the radius fixation plate 2 to the radius 3 across a fractured portion 3a of the radius 3, in order to facilitate the screw tightening operation of rotating the fixing screw 4 with the tool 1 for fixing a radius fixation plate 2, a guide block 5 as shown in Figs. 2 and 3 is placed on the radius fixation plate 2, and then the screw tightening operation is performed using a screw insertion hole 5d of the guide block 5. After the radius fixation plate 2 is fixed to the radius 3, the guide block 5 is removed from the radius fixation plate 2. However, as will be described later in a modified example, the guide block 5 does not have to be used.

[0017] 1, the fractured portion 3a of the radius 3 is divided into a radius body 3b and a fractured fragment 3c by the fractured portion 3a. The radius body 3b and the fractured fragment 3c may be completely separated or may be partially connected.

[0018] The radius fixation plate 2 is placed on the radius 3 so that the fractured fragment 3c is fixed in a state in which it is normally connected to the radius body 3b.

[0019] The radial fixation plate 2 is made of, for example, a thermoplastic resin or a composite material thereof. Examples of the thermoplastic resin include PEEK (polyether ether ketone) and polyetherimide.

[0020] As an example, the radius fixation plate 2 is a T-shaped plate member made up of a wide distal portion 2a and a proximal portion 2b extending from the distal portion 2a. In this specification, the "proximal portion" refers to a portion of the radius fixation plate 2 that is closer to the heart, and the "distal portion" refers to a portion of the radius fixation plate 2 that is farther from the heart than the proximal portion.

[0021] The distal portion 2a is fixed to the fracture fragment 3c with a plurality of screws 4, and the proximal portion 2b is fixed to the radial body 3b with a plurality of screws 4, so that the radius fixation plate 2 straddles the fracture fragment 3a and the fracture fragment 3c is normally connected to the radial body 3b.

[0022] The distal portion 2a and the proximal portion 2b each have a large number of circular screw insertion holes 2d extending in the axial direction in the thickness direction of the radius fixation plate 2 or in a direction in which the tip is inclined outward with respect to the thickness direction. If necessary, a fixing screw 4 is inserted into the screw insertion hole 2d, and the fixing screw 4 is screwed into both a part of the screw insertion hole 2d of the radius fixation plate 2 and the radius 3 to fix the radius fixation plate 2 to the radius 3. As shown in Figs. 4 to 6, each screw insertion hole 2d is composed of a large-diameter head storage portion 2e and a small-diameter female screw portion 2f that is smaller than the inner diameter of the head storage portion 2e.

[0023] As shown in FIGS. 4 to 6, the fixing screw 4 to be inserted into the screw insertion hole 2d is made of hard metal, and is composed of a head 4c and a shaft 4a connected to the head 4c.

[0024] The shaft portion 4a has a diameter smaller than the inner diameter of the female thread portion 2f of the screw insertion hole 2d and can pass through the female thread portion 2f. A main screw 4b that self-taps on the radius 3 after passing through the screw insertion hole 2d is formed on the shaft portion 4a.

[0025] As an example, the head 4c has an outer diameter equal to the inner diameter of the female threaded portion 2f, and is accommodated in the head accommodation portion 2e when the screw is fastened. A sub-thread 4d is formed on the outer peripheral surface of the shaft portion side of the head 4c, and is screwed into the female threaded portion 2f of the screw insertion hole 2d. Instead of the sub-thread 4d being screwed into the female threaded portion 2f, the female threaded portion 2f may be formed as a threaded portion without a female thread being formed in advance, and the sub-thread 4d may be screwed into the threaded portion by performing a self-tapping action.

[0026] A hexalobular hole 4j is formed on the top surface of the head 4c, and a screw coupling portion 12c of a rotating shaft portion 12 of the tool 1 described later is coupled thereto, thereby enabling the fixing screw 4 to rotate forward and backward. The hexalobular hole 4j is an example, but it is preferable because the hexalobular hole 4j and the screw coupling portion 12c in the shape of a hexalobular wrench come into contact with each other at the crests and the roots, and do not slip unless both are completely smoothed. In other words, the hexalobular hole 4j has the effect of efficiently transmitting the tightening torque and reducing the risk of damage to the tool or the head of the screw by eliminating stress concentration.

[0027] As shown in Figures 4 to 6, the guide block 5 is a component that is placed on top of the radius fixation plate 2 to facilitate the screw tightening operation when the fixation screw 4 is rotated with the radius fixation plate fixation screw tool 1.

[0028] 2 and 3, the outer shape of the guide block 5 is the same as that of the radius fixation plate 2, so that it covers the entire radius fixation plate 2 and is easy to stack. Specifically, the guide block 5 includes a wide distal portion 5a having the same shape as the wide distal portion 2a of the radius fixation plate 2, and a proximal portion 5b extending from the distal portion 5a and having the same shape as the proximal portion 2b of the radius fixation plate 2, forming a T-shaped member. The guide block 5 makes it easier to guide the fixation screw 4 than when there is no guide block.

[0029] 3, the outer periphery of the back surface of the guide block 5 has holding claws 5c that can be engaged and held on the outer periphery of the radius fixing plate 2. Holding with the holding claws 5c is just one example, and the guide block 5 may be fixed to the radius fixing plate 2 by a fixing method other than the holding claws 5c, such as a dedicated screw or a dual-purpose screw.

[0030] The distal portion 5a and the proximal portion 5b are each formed with a large number of circular screw insertion holes 5d extending in the axial direction in the thickness direction of the guide block 5 or in the direction in which the tip is inclined outward with respect to the thickness direction, in other words, in the thickness direction of the radius fixation plate 2 or in the direction in which the tip is inclined with respect to the thickness direction. Each screw insertion hole 5d is formed and arranged in correspondence with each screw insertion hole 2d.

[0031] As shown in Fig. 4, each screw insertion hole 5d is composed of a large-diameter center tube guide portion 5e and a small-diameter rotating shaft portion through-hole 5f that is smaller than the inner diameter of the center tube guide portion 5e. A center tube regulating portion 5h composed of an annular edge is formed at the boundary between the center tube guide portion 5e and the rotating shaft portion through-hole 5f. The center tube regulating portion 5h is contacted with the tip of a center tube 13 of a tool 1 described later, and the center tube 13 is regulated in position so that it does not enter the rotating shaft portion through-hole 5f in each screw insertion hole 5d beyond the center tube regulating portion 5h.

[0032] As shown in Figs. 4 to 15, the tool 1 for fixing a radial fixation plate screw includes at least a rotational force input portion 11, a rotating shaft portion 12, a middle cylinder 13, and an outer cylinder 14. For example, the tool 1 may be entirely made of metal, or the middle cylinder 13 and the outer cylinder 14 may be made of synthetic resin and the remaining portion may be made of metal. The tool 1 for fixing a radial fixation plate screw may further include a biasing member 15. Figs. 4 to 6 are diagrams showing an outline of the tool 1, and Figs. 7 to 15 are diagrams showing a specific configuration of the tool 1, but the functions of both are almost the same. In particular, the major difference is that the shapes of the first engagement protrusion 13c and the second engagement protrusion 14c are simplified and illustrated as gear shapes rather than plate shapes with trapezoidal cross sections as described later, but the functions are the same.

[0033] The rotational force input unit (rotational force input member) 11 is a part that applies a rotational force around an axis to the tool 1, and is composed of a rod-shaped member. As an example, the rotational force input unit 11 may be connected to a surgical tool, and the rotational force from the surgical tool may be input to the rotational force input unit 11 to enable the tool 1 to rotate forward and backward around the axis. As another example, when rotating by hand, the tool 1 may have a flat surface portion 11a extending in the axial direction, and may be rotated forward and backward around the axis by pinching the flat surface portion 11a and the curved back surface portion of the flat surface portion 11a with fingers. The flat surface portion 11a is not necessarily required since the rotational force input unit 11 only needs to rotate forward and backward around the axis to fasten and release the fastening screw 4. The tip of the rotational force input unit 11 has a cylindrical fitting recess 11b.

[0034] As shown in Figures 7 to 10, the rotating shaft portion (rotating shaft member) 12 is arranged coaxially with the rotational force input portion 11, and includes a shaft main body 12a having a hexagonal cross-section, a tapered screw connection portion 12c at the tip of the shaft main body 12a, a cylindrical fitting protrusion 12d arranged at the base end of the shaft main body 12a, and annular spring locking protrusion 12e protruding radially beyond the outer diameter of the shaft main body 12a near the base end of the shaft main body 12a.

[0035] The fitting protrusion 12d is fitted and connected in a cylindrical fitting recess 11b at the tip of the rotational force input portion 11 so as to be relatively rotatable about the axis. Thus, the shaft main body 12a extends in the axial direction from the tip of the rotational force input portion 11 via the fitting protrusion 12d and is rotatable relatively to the rotational force input portion 11. The method of connecting the rotating shaft portion 12 and the rotational force input portion 11 may be such that the relationship between the protrusion and the recess is reversed.

[0036] The screw coupling portion 12c is disposed at the tip of the shaft main body 12a, and is a hexalobular screw rotation portion that can be coupled to the hexalobular hole 4j of the head 4c of the fixing screw 4 so as not to rotate relatively, and allows the fixing screw 4 to rotate forwards and backwards in order to fasten or release the fixing screw 4. The screw coupling portion 12c is configured as a hexalobular screw rotation portion in the shape of a hexalobular wrench that can engage with the hexalobular hole 4j of the head 4c when a hexalobular screw 4 is used as the fixing screw 4.

[0037] As shown in FIGS. 7 to 9 and 11 to 13, the middle cylinder 13 is made up of a cylindrical member.

[0038] The center cylinder 13 includes a center cylinder main body 13a and a first engagement projection 13c that projects radially from the outer circumferential surface of the base end of the center cylinder main body 13a.

[0039] The middle tube body 13a is arranged on the outer peripheral surface of the base end side of the hexagonal cross-sectional shaft body 12a of the rotating shaft portion 12, and has a hexagonal cross-sectional through hole 13b as an example that is not rotatable relative to the hexagonal cross-sectional shaft body 12a around the axis, in other words, is rotatable integrally with the hexagonal cross-sectional shaft body 12a, and is movable in the axial direction between a rotation position A and an idling position B.

[0040] The threaded coupling portion 12c at the tip of the rotating shaft portion 12 always protrudes from the tip of the middle cylinder body 13a.

[0041] In the vicinity of the base end of the shaft body 12a, a coil spring 15 as an example of a biasing member 15 is arranged in a slightly compressed state between the annular base end surface 13d of the middle tube body 13a and the annular spring locking projection 12e, and the spring force of the coil spring 15 constantly biases the middle tube body 13a toward the tip side relative to the shaft body 12a, so that the middle tube body 13a is always located at the rotation position A, not the idling position B. However, the coil spring 15 is not necessarily required. For example, in the tool 1 with a simple configuration, the coil spring 15 can be omitted, and the middle tube 13 can be returned by hand to the initial position, the rotation position A, every time the fixing screw 4 is fastened, and the tool can be used while being careful not to move the middle tube 13 during the fastening operation of the fixing screw. Even in such a case, the idling operation described above can be performed at the idling position B.

[0042] As an example, the first engagement protrusion 13c is formed in a plate shape with a trapezoidal cross section curved in the radial direction, with one or more in the circumferential direction. For example, four first engagement protrusions 13c are formed at predetermined intervals, for example, at intervals of 90 degrees, and the space on the outer circumferential surface between adjacent first engagement protrusions 13c functions as a first engagement recess 13e into which a second engagement protrusion 14c described later enters in the axial direction so as to be removable. The tip side of each first engagement protrusion 13c has an inclined surface 13g that is inclined so as to approach the center in the radial direction as it approaches the tip in the axial direction, so that engagement and disengagement with the second engagement protrusion 14c described later can be smoothly performed.

[0043] The outer cylinder 14 is configured as a cylindrical member having a diameter larger than that of the middle cylinder 13 and having a tapered shape.

[0044] The outer tube 14 is arranged outside the middle tube 13 so as to be relatively movable in the axial direction, and is equipped with an outer tube main body 14a having a circular through hole 14b, and a second engagement protrusion 14c formed on the inner surface of the middle part of the outer tube main body 14a and protruding toward the radial center, and engageable with the first engagement protrusion 13c.

[0045] The through hole 14b has a large inner diameter on the base end side and the diameter gradually or stepwise decreases toward the tip end, so that the inner cylinder 13 cannot be separated from the outer cylinder 14 in the axial direction toward the tip end.

[0046] The outer cylinder 14 is disposed so that the tip end portion of the middle cylinder 13 is exposed from the tip of the outer cylinder 14 and covers the base end portion of the middle cylinder 13, the base end portion of the rotating shaft portion 12, and the tip portion of the rotational force input portion 11. Furthermore, a fixing pin 16 is inserted diametrically into the tip portion of the rotational force input portion 11 and the base end portion of the outer cylinder 14 to fix the tip portion of the rotational force input portion 11 to the base end portion of the outer cylinder 14. Thus, the rotational force input portion 11 and the outer cylinder 14 are configured to rotate forward and backward integrally.

[0047] As an example, the second engagement protrusion 14c of the outer cylinder 14 is formed as one or more in the circumferential direction, and is a plate shape with a trapezoidal cross section curved in the radial direction. For example, the second engagement protrusion 14c is formed in a number of four at predetermined intervals, for example, at intervals of 90 degrees, and the space on the outer circumferential surface between adjacent second engagement protrusions 14c functions as a second engagement recess 14e into which the first engagement protrusion 13c enters in the axial direction so as to be removable.

[0048] Therefore, the first engagement protrusion 13c can advance and retreat in the axial direction relative to the second engagement recess 14e between a rotation position A and an idling position B. At the rotation position A, the first engagement protrusion 13c enters the second engagement recess 14e, and the first engagement protrusion 13c and the second engagement protrusion 14c are engaged with each other about the axis, and are unable to rotate relatively about the axis. At the idling position B, the first engagement protrusion 13c is pulled out of the second engagement recess 14e, and the engagement between the first engagement protrusion 13c and the second engagement protrusion 14c about the axis is released, and they are able to rotate relatively about the axis.

[0049] At the same time, within the first engagement recess 13e, the second engagement protrusion 14c can advance and retreat in the axial direction between the rotation position A and the idling position B. At the rotation position A, the second engagement protrusion 14c enters the first engagement recess 13e, and the first engagement protrusion 13c and the second engagement protrusion 14c are engaged with each other about the axis, and are unable to rotate relatively about the axis. At the idling position B, the second engagement protrusion 14c is pulled out of the first engagement recess 13e, and the engagement between the first engagement protrusion 13c and the second engagement protrusion 14c about the axis is released, and they are able to rotate relatively about the axis.

[0050] The base end side of each second engagement protrusion 14c has an inclined surface 14g that is inclined so as to approach the radial center as it approaches the tip in the axial direction, and the inclined surface 14g is capable of sliding against the inclined surface 13g of the first engagement protrusion 13c, allowing smooth engagement and disengagement with the first engagement protrusion 13c around the axis.

[0051] The coil spring 15 is positioned near the base end of the rotating shaft portion 12 with a gap between it and the rotating shaft portion 12 so as not to interfere with the forward and reverse rotation of the rotating shaft portion 12, and constantly biases the middle tube 13 toward the tip side along the axial direction so that the middle tube 13 is positioned at rotation position A.

[0052] The tool 1 having such a configuration can be used as follows.

[0053] First, the guide block 5 is placed on the radius fixation plate 2 and held in place using a fixing method such as the retaining claws 5c, dedicated screws, or dual-purpose screws. Then, as shown in Figure 4, the guide block 5 and the radius fixation plate 2 are placed together on the radius 3 so that the radius fixation plate 2 straddles the fractured portion 3a of the radius 3.

[0054] 4, a fixing screw 4 is inserted into one screw insertion hole 5d of the guide block 5 and the screw insertion hole 2d of the radius fixation plate 2, and the screw coupling portion 12c of the rotating shaft portion 12 of the tool 1 is coupled into the hexalobular hole 4j of the head 4c of the fixing screw 4. In this state, the screw insertion hole 2d, the screw insertion hole 5d, the fixing screw 4, and the tool 1 are held coaxially with each other.

[0055] Next, the rotational force input unit 11 of the tool 1 starts to rotate in the direction of fastening the fixing screw 4. As a result, the rotational force from the rotational force input unit 11 is transmitted to the outer tube 14, the middle tube 13 biased to the rotational position A by the coil spring 15, the rotational shaft unit 12, and the fixing screw 4, and the fixing screw 4 is screwed into the radius 3 while being guided by the screw insertion hole 5d of the guide block 5. That is, since the middle tube 13 is located at the rotational position A, the rotational force from the outer tube 14 is reliably transmitted to the middle tube 13 by the engagement of the first engagement protrusion 13c and the second engagement protrusion 14c around the axis. At this time, the screw insertion hole 5d of the guide block 5 guides the fixing screw 4 so that it advances smoothly in its axial direction, and the shaft unit 4a of the fixing screw 4 starts to be screwed into the radius 3. When the fixing screw 4 is screwed in, the main thread 4b of the shaft unit 4a of the fixing screw 4 performs a self-tapping action on the radius 3 and is screwed in.

[0056] Next, as shown in FIG. 5, as the fixing screw 4 continues to rotate in the tightening direction and is screwed into the radius 3, the center tube 13 advances in the center tube guide portion 5e of the screw insertion hole 5d, and the center tube 13 comes into contact with the center tube regulating portion 5h. As the fixing screw 4 continues to rotate in the tightening direction even after the contact, the center tube 13 starts to retreat relative to the rotating shaft portion 12 as the fixing screw 4 continues to be screwed further into the radius 3 and advances in the axial direction. This means that the center tube 13 starts to move from the rotation position A toward the idling position B. At this time, as an example, the auxiliary thread 4d of the head 4c of the fixing screw 4 is screwed into the female thread portion 2f of the screw insertion hole 2d of the radius fixation plate 2 or performs a self-tapping action, so that the radius fixation plate 2 is fixed in close contact with the radius 3.

[0057] As a result, as shown in FIG. 6, the fixing screw 4 is located at a predetermined position (so to speak, a fixing screw fastening position) with respect to the radius fixation plate 2. Here, the predetermined position is, for example, a position where the head 4c of the fixing screw 4 contacts the countersunk surface of the screw insertion hole 2d of the radius fixation plate 2 (i.e., the boundary between the head storage section 2e and the female screw section 2f). At this time, the lower end of the head 4c of the fixing screw 4 is located at a position up to a certain distance (for example, 2 mm) from the countersunk surface of the screw insertion hole 2d. However, this is only an example, and the predetermined position may be a position shifted toward the opening side of the head storage section 2e from the countersunk surface, or conversely, may be a position that is inserted into the female screw section 2f side from the countersunk surface. When the fixing screw 4 is located at such a predetermined position, if the tool 1 moves the center cylinder 13 from the rotation position A to the idling position B, the engagement between the first engagement protrusion 13c and the second engagement protrusion 14c around the axis is released. Then, the outer cylinder 14 rotates idly relative to the middle cylinder 13, and it becomes impossible to transmit any more rotational force from the tool 1 to the fixing screw 4, and the screw tightening operation becomes impossible. As a result, the fixing screw 4 is maintained in a predetermined position relative to the radius fixation plate 2, and the depth and rotation of the fixing screw 4 are restricted. Note that the certain distance is determined by the thickness of the radius fixation plate 2 or the thickness of the head 4c of the fixing screw 4, and varies, so it is difficult to uniformly prescribe the certain distance, and so it is illustrated as an example.

[0058] When releasing the fastening, the fixing screw 4 can be loosened and removed by rotating the rotating shaft portion 12 in the reverse direction using the tool 1 or a general screwdriver without using the guide block.

[0059] According to the first embodiment, at the rotation position A of the middle cylinder 13, the first engagement protrusion 13c and the second engagement protrusion 14c are engaged with each other, and the rotation force generated when the rotation force input portion 11 is rotated is transmitted to the rotating shaft portion 12 via the outer cylinder 14 and the middle cylinder 13, and the fixing screw 4 connected to the rotating shaft portion 12 is rotated in the fastening direction. On the other hand, when the fixing screw 4 is screwed into the radius 3 by a predetermined distance, the middle cylinder 13 comes into contact with the guide block 5 arranged on the radius fixing plate 2, and the middle cylinder 13 is moved backward toward the rotation force input portion 11 side relative to the rotating shaft portion 12. This means that the middle cylinder 13 moves in the axial direction from the rotation position A to the idling position B, and the engagement between the first engagement protrusion 13c and the second engagement protrusion 14c around the axis is released. Then, even if the outer tube 14 rotates by rotating the rotational force input portion 11, the outer tube 14 and the middle tube 13 rotate idly, and the rotational force from the outer tube 14 is not transmitted to the rotating shaft portion 12, so that the rotation is restricted, and the fixing screw 4 is not screwed in beyond the predetermined dimension, so that the depth can be restricted. Therefore, the tightening depth restriction and the rotation restriction of the fixing screw 4 of the resin radius fixation plate 2 can be easily and reliably implemented. That is, by moving the middle tube 13 from the rotation position A to the idling position B to disengage, the depth restriction and the rotation restriction can be implemented, so that excessive tightening force is not applied to the fixing screw 4 and the radius fixation plate 2 any more.

[0060] The present invention is not limited to the first embodiment, and can be embodied in various other modes. For example, as shown in Fig. 16A to Fig. 16D, when the guide block 5 is not used, the radius fixing plate 2 may be provided with a center tube regulating portion 2h as an edge portion as a position regulating portion for contacting the center tube 13 to move the center tube 13 from the rotation position A to the idling position B. That is, instead of forming the screw insertion hole 2d of the radius fixing plate 2 with the head storage portion 2e and the female thread portion 2f, a center tube guide portion 2j corresponding to the center tube guide portion 5e and a rotating shaft portion penetrating portion 2k corresponding to the rotating shaft portion penetrating portion 5f, which have an inner diameter larger than that of the head storage portion 2e, are formed in a portion closer to the opening side of the screw insertion hole 2d than the head storage portion 2e, and a center tube regulating portion 2h corresponding to the center tube regulating portion 5h is provided in the boundary portion between the two. As a result, as the fixing screw 4 continues to rotate in the fastening direction and is screwed into the radius 3, the center cylinder 13 advances within the center cylinder guide portion 2j of the screw insertion hole 2d, and the center cylinder 13 comes into contact with the center cylinder regulating portion 2h. As the fixing screw 4 continues to rotate in the fastening direction even after the contact, it is further screwed into the radius 3 and advances in the axial direction, and the center cylinder 13 begins to retreat relative to the rotating shaft portion 12. This means that the center cylinder 13 begins to move from the rotating position A toward the idling position B. The subsequent operations are the same as those in the first embodiment.

[0061] According to this modification, the depth position regulation and rotation regulation by the tool 1 can be performed without using the guide block 5.

[0062] A tool 71 for fixing a radial fixation plate screw according to the second embodiment of the present invention is a tool that can be used in the same manner as the tool 1 for fixing a radial fixation plate screw shown in FIG.

[0063] Each screw insertion hole 5d of the radius fixation plate 2 is provided with a rotation stopper notch 5g, which is cut radially at predetermined circumferential positions, for example, at 120-degree intervals around the axis, as an example of a first rotation stopper portion. Rotation stopper protrusions 8g, which protrude radially at 120-degree intervals on the outer circumferential surface of the guide tube 8 of the tool 71, as an example of a second rotation stopper portion described later, fit into and engage with the rotation stopper notch 5g, thereby restricting the rotation of the rotating shaft portion 12 and preventing it from rotating.

[0064] As shown in Figure 21 etc., similar to the first embodiment, the fixing screw 4 inserted into the screw insertion hole 2d is made of hard metal and is composed of a head 4c and a shaft 4a connected to the head 4c.

[0065] As shown in Figs. 2-3 and 21, the inner tube guide portion 5e of each screw insertion hole 5d can be read as the guide tube guide portion 5e. Therefore, each screw insertion hole 5d is composed of a large-diameter guide tube guide portion 5e and a small-diameter rotary shaft portion through-hole 5f that is smaller than the inner diameter of the guide tube guide portion 5e. A guide tube restricting portion 5h composed of an annular edge portion is formed at the boundary between the guide tube guide portion 5e and the rotary shaft portion through-hole 5f. The guide tube restricting portion 5h is contacted with the tip of a guide tube 8 of a tool 71 described later, and the guide tube 8 is restricted in position so as not to enter the rotary shaft portion through-hole 5f in each screw insertion hole 5d beyond the guide tube restricting portion 5h.

[0066] 17 to 20, a tool 71 for a radius fixation plate fixing screw is composed of a main body 7 and a guide tube 8 which is a separate member from the main body 7. As an example, the main body 7 and the guide tube 8 can be made of a metal such as stainless steel.

[0067] The main body 7 includes a rotational force input portion (rotational force input member) 81 and a rotating shaft portion (rotating shaft member) .

[0068] The rotational force input unit 81 is a part that applies a rotational force around an axis to the tool 71, and is composed of a rod-shaped member. As an example, the rotational force input unit 81 may be connected to a surgical tool, and the rotational force from the surgical tool may be input to the rotational force input unit 81 to enable the tool 71 to rotate forward and backward around the axis. As another example, when rotating by hand, the tool 71 may have a flat surface portion 81a extending in the axial direction, and may be rotated forward and backward around the axis by pinching the flat surface portion 81a and the curved back surface portion of the flat surface portion 81a with fingers. The flat surface portion 81a is not necessarily required for the rotational force input unit 81 as long as it can rotate forward and backward around the axis to fasten and release the fixing screw 4.

[0069] The rotating shaft portion 82 is disposed coaxially with the rotational force input portion 81, and includes a shaft portion main body 82a having a circular cross section, a tapered screw coupling portion 82c at the tip of the shaft portion main body 82a, and a first engagement portion disposed on the base end side of the shaft portion main body 82a, i.e., at or near the base end. The shaft portion main body 82a may be integrally formed with the rotational force input portion 81 as a single member, or may be formed as a separate member from the rotational force input portion 81 and connected thereto.

[0070] The screw coupling portion 82c is disposed at the tip of the shaft main body 82a, and is a hexalobular screw rotation portion that can be coupled to the hexalobular hole 4j in the head 4c of the fixing screw 4 so as not to rotate relatively, and allows the fixing screw 4 to rotate forwards and backwards in order to fasten or release the fixing screw 4. When a hexalobular screw is used as the fixing screw 4, the screw coupling portion 82c is configured as a hexalobular screw rotation portion in the shape of a hexalobular wrench that can engage with the hexalobular hole 4j in the head 4c.

[0071] The shaft body 82a is provided at its base end with a ring-shaped protrusion 82k that protrudes in the radial direction. The ring-shaped protrusion 82k functions as an example of a third engagement portion, which will be described later.

[0072] A first engagement portion 82j is formed adjacent to the annular protrusion 82k on the tip side of the shaft body 82a. The first engagement portion 82j is, as an example, configured with a male screw. The male screw of the first engagement portion 82j is formed to be smaller in the radial direction than the outer diameter of the annular protrusion of the annular protrusion 82k.

[0073] As shown in Figs. 18 to 20, the guide cylinder 8 is configured of a cylindrical member into which a rotating shaft portion 82 is inserted so as to be relatively movable in the axial direction and relatively rotatable about the axis.

[0074] The guide tube 8 includes a guide tube main body 8m and an annular projection 8n that projects radially from the outer circumferential surface of the base end of the guide tube main body 8m and has a base end surface 8k as an example of a fourth engagement portion. The inner diameters of the guide tube main body 8m and the annular projection 8n are the same, so that the rotating shaft 82a can be inserted so as to be able to smoothly advance and retreat in the axial direction and to be able to rotate forward and backward around the axis. As described later, the base end surface 8k comes into contact with an annular projection 82k, so that the relative axial movement of the rotating shaft 82 toward the tip side with respect to the guide tube 8 can be restricted.

[0075] The length of the guide tube 8 can be determined taking into consideration the length of the screw insertion hole 2d in the radius fixation plate 2 and the length of the rotation shaft portion through-hole 5f of the screw insertion hole 5d in the guide block 5 so that when the guide block 5 is placed on the radius fixation plate 2 and the fixation screw 4 is screwed into the radius 3, the screwing depth (i.e., the depth) of the fixation screw 4 screwed into the radius 3 will be a predetermined dimension.

[0076] A female thread into which the male thread of the first engagement portion 82j is screwed is formed on the inner circumferential surface of the annular protrusion 8n as an example of the second engagement portion 8j. When the male thread of the first engagement portion 82j is completely screwed into the female thread of the second engagement portion 8j, the annular protrusion 82k comes into contact with the base end face 8k, and the first engagement portion 82j cannot be screwed further into the second engagement portion 8j. As a result, the contact between the annular protrusion 82k and the base end face 8k restricts the depth and rotation of the fixing screw 4.

[0077] The pitch of the female thread of the second engagement portion 8j and the male thread of the first engagement portion 82j can be the same as the pitch of the sub-thread 4d of the head 4c of the fixing screw 4.

[0078] The reason for making the pitches the same is to avoid the following problems.

[0079] First, when the thread pitch of the female thread of the second engagement portion 8j and the male thread of the first engagement portion 82j is larger than the thread pitch of the secondary thread 4d of the head 4c, a load equivalent to the pitch difference is applied between the guide tube 8 and the guide block 5, or between the tip of the screw connection portion 82c of the rotating shaft portion 82 and the fixing screw 4, or between the fixing screw 4 and the female thread portion 2f of the radius fixation plate 2, which may result in premature wear or damage to each component or damage to the female thread portion 2f of the radius fixation plate 2.

[0080] Furthermore, when the pitch of the female thread of the second engagement portion 8j and the male thread of the first engagement portion 82j is larger than the pitch of the sub-thread 4d of the head 4c, a gap begins to form between the tip of the screw coupling portion 82c of the rotating shaft portion 82 and the fixing screw 4. In other words, this means a state in which the tip of the screw coupling portion 82c of the rotating shaft portion 82 is not properly engaged with the fixing screw 4. This causes the tip of the screw coupling portion 82c of the rotating shaft portion 82 to be "stripped."

[0081] If it is necessary to prevent these problems from occurring, the pitch may be made the same as described above.

[0082] On the outer peripheral surface of the guide tube main body 8m of the guide tube 8, rotation stopper protrusions 8g for preventing rotation in the radial direction are formed at predetermined circumferential positions, for example, at intervals of 120 degrees around the axis, so as to protrude radially and extend along the axial direction. Therefore, when a part of the lower side of the guide tube 8 is inserted into the guide tube guide portion 5e of one screw insertion hole 5d of the guide block 5, the three rotation stopper protrusions 8g of the guide tube 8 are fitted into the three rotation stopper notches 5g of the male screw insertion hole 5d to lock the guide tube 8 around the axis, thereby preventing the guide tube 8 from rotating relative to the screw insertion hole 5d. In this way, the first rotation stopper and the second rotation stopper are locked at intervals of 120 degrees, in other words, evenly around the axis, so that the rotation around the axis can be smoothly and reliably restricted compared to the case where the rotation stopper parts are arranged unevenly.

[0083] The tool 71 having such a configuration can be used as follows.

[0084] First, the guide block 5 is placed on the radius fixation plate 2 and held in place using a fixing method such as the retaining claws 5c, dedicated screws, or dual-purpose screws. Then, as shown in Figure 21, the guide block 5 and the radius fixation plate 2 are placed together on the radius 3 so that the radius fixation plate 2 straddles the fractured portion 3a of the radius 3.

[0085] Next, a part of the lower side of the guide tube 8 is inserted into the guide tube guiding portion 5e of one of the screw insertion holes 5d of the guide block 5, and the tip of the guide tube 13 is brought into contact with the guide tube regulating portion 5h, and the rotation stop protrusion 8g of the guide tube 8 is fitted into the rotation stop notch 5g of the male screw insertion hole 5d, thereby preventing the guide tube 8 from rotating relative to the screw insertion hole 5d. In this state, the fixing screw 4 is inserted into the guide tube 8.

[0086] Next, the rotating shaft 82 of the main body 7 is inserted into the guide tube 8, and the screw coupling portion 82c of the rotating shaft 82 of the tool 71 is coupled into the hexalobular hole 4j of the head 4c of the fixing screw 4. In this state, the screw insertion hole 2d, the screw insertion hole 5d, the fixing screw 4, and the tool 71 are held coaxially with each other.

[0087] Next, the rotational force input unit 81 of the tool 71 starts to rotate in the direction of fastening the fixing screw 4. As a result, the rotational force from the rotational force input unit 81 is transmitted to the rotating shaft unit 82 and the fixing screw 4, and the fixing screw 4 is screwed into the radius 3 while being guided by the screw insertion hole 5d of the guide block 5. At this time, the shaft unit 4a of the fixing screw 4 starts to be screwed into the radius 3 while the screw insertion hole 5d of the guide block 5 guides the fixing screw 4 so that it advances smoothly in its axial direction. When the fixing screw 4 is screwed, the main thread 4b of the shaft unit 4a of the fixing screw 4 performs a self-tapping action on the radius 3 and is screwed in. When the fixing screw 4 is screwed into the radius 3 to a certain extent, the male thread of the first engagement unit 82j of the rotating shaft unit 82 starts to be screwed into the female thread of the second engagement unit 8j. At this time, as an example, the auxiliary thread 4d of the head 4c of the fixing screw 4 is screwed into the female thread portion 2f of the screw insertion hole 2d of the radius fixing plate 2, so that the radius fixing plate 2 is fixed in close contact with the radius 3.

[0088] As a result, as shown in FIG. 22, the fixing screw 4 is located at a predetermined position (so to speak, a fixing screw fastening position) with respect to the radius fixation plate 2. Here, the predetermined position is, for example, a position where the head 4c of the fixing screw 4 contacts the countersunk surface of the screw insertion hole 2d of the radius fixation plate 2 (i.e., the boundary between the head storage section 2e and the female thread section 2f). At this time, the lower end of the head 4c of the fixing screw 4 is located at a position up to a certain distance (for example, 2 mm) from the countersunk surface of the screw insertion hole 2d. However, this is only one example, and the predetermined position may be a position shifted toward the opening side of the head storage section 2e from the countersunk surface, or conversely, may be a position that is inserted into the female thread section 2f side from the countersunk surface. When the fixing screw 4 is located at such a predetermined position, the annular protrusion 82k contacts the base end surface 8k with the tool 71, and the first engagement section 82j cannot be screwed further into the second engagement section 8j. As a result, due to contact between the annular protrusion 82k and the base end face 8k, it becomes impossible to transmit any more rotational force from the tool 71 to the fixing screw 4, and the screw tightening operation cannot be performed. This maintains the fixing screw 4 in a predetermined position relative to the radius fixation plate 2, and restricts the depth and rotation of the fixing screw 4. Note that the certain distance is determined by the thickness of the radius fixation plate 2 or the thickness of the head 4c of the fixing screw 4, and varies, so it is difficult to uniformly prescribe the certain distance, and is therefore illustrated as an example.

[0089] When releasing the fastening, the fixing screw 4 can be loosened and removed by rotating the rotating shaft portion 82 in the reverse direction using the tool 71 or a general screwdriver without using a guide block.

[0090] According to the second embodiment, the rotational force input unit 81 is rotated with respect to the guide tube 8 inserted into the screw insertion hole 5d of the radius fixation plate 2 or the guide block 5, and the fixing screw 4 is started to be screwed into the radius 3 by rotating the rotation shaft unit 82. Thereafter, when the fixing screw 4 is screwed into the radius 3 and the fastening depth of the fixing screw 4 reaches a predetermined dimension, the annular protrusion unit 82k and the base end face 8k come into contact and engage with each other. At this time, the rotation shaft unit 82 cannot rotate any further and the fixing screw 4 cannot be screwed into the radius 3 together with the rotation shaft unit 82, so that the depth can be restricted. At the same time, the male thread of the first engagement unit 82j and the female thread of the second engagement unit 8j are screwed into each other, so that the annular protrusion unit 82k and the base end face 8k come into contact and engage with each other, so that the rotation shaft unit 82 cannot rotate, and excessive rotation can be suppressed, and rotation can also be restricted.

[0091] The present invention is not limited to the second embodiment, and can be embodied in various other modes. For example, as shown in FIG. 23, when the guide block 5 is not used, a rotation stop notch 2g similar to the rotation stop notch 5g is formed in the male screw insertion hole 2d as shown in FIG. 1. That is, in each screw insertion hole 2d of the radius fixation plate 2, a rotation stop notch 2g cut radially at a predetermined position in the circumferential direction, for example, at intervals of 120 degrees around the axis, is arranged as an example of a third rotation stopper. As with the rotation stop notch 5g, the rotation stopper protrusions 8g protruding radially at intervals of 120 degrees from the outer circumferential surface of the guide tube 8 of the tool 71 as an example of a second rotation stopper enter and engage with the rotation stopper notch 2g, thereby restricting the rotation of the rotating shaft portion 82 so that it does not rotate, thereby preventing the rotation from being stopped. At this time, the inner diameter of the screw insertion hole 2d is made larger than the outer diameter of the guide tube main body 8m so that at least a part of the screw insertion hole 2d enters the guide tube main body 8m.

[0092] Therefore, while holding the guide tube 8 with one hand along the axial direction of the screw insertion hole 2d of the radius fixation plate 2, the guide tube 8 is inserted into the screw insertion hole 2d, and the rotation stop protrusion 8g enters and engages with the rotation stop notch 2g, restricting the rotation of the rotating shaft portion 82 and preventing it from rotating. Next, with the other hand, the fixing screw 4 is inserted into the guide tube 8, and the rotating shaft portion 82 is inserted, and the rotating shaft portion 82 is rotated in the same manner as in the previous second embodiment, whereby the fixing screw 4 is screwed in, and the first engagement portion 82j is screwed into the second engagement portion 8j.

[0093] Thereafter, when the tightening depth of the fixing screw 4 reaches a predetermined dimension, the first engagement portion 82j can no longer be screwed into the second engagement portion 8j, and the annular protrusion portion 82k comes into contact with and engages with the base end face 8k, preventing the rotating shaft portion 82 from rotating and advancing any further. As a result, the fixing screw 4 cannot be screwed into the radius 3 together with the rotating shaft portion 82, and rotation and depth restrictions can be performed.

[0094] According to this modification, the depth position regulation and rotation regulation can be performed by the tool 71 without using the guide block 5.

[0095] In addition, by appropriately combining any of the various embodiments or modifications described above, it is possible to achieve the effects of each of them. In addition, combinations of embodiments, combinations of examples, or combinations of embodiments and examples are possible, and combinations of features of different embodiments or examples are also possible. Although the present invention has been fully described in connection with the preferred embodiment with reference to the accompanying drawings, various changes and modifications will become apparent to those skilled in the art, and such changes and modifications are to be understood as being included within the scope of the present invention as defined by the appended claims, unless they depart therefrom. [Industrial Applicability]

[0096] The tool for fixing screws of a radius fixation plate according to the above aspect of the present invention can easily and reliably regulate the tightening depth and rotation of the fixing screws of a resin radius fixation plate. [Explanation of symbols]

[0097] 1 Radial Plate Fixation Screw Tool 2 Radial Fixation Plate 2a Distal part 2b Proximal part 2d screw insertion hole 2e Head storage section 2f Female thread 2h Middle cylinder regulation part 2j Middle cylinder guide part 2k Rotating shaft penetration 3 Radius 3a Fracture area 3b Radial body 3c fracture fragment 4 Fixing screws 4a Shaft 4b Lead screw 4c head 4d Sub-screw 4j hexalobular hole 5 Guide Block 5a Distal 5b Proximal part 5c retaining claw 5d screw insertion hole 5e Center tube guide section (guide tube guide section) 5f Rotating shaft penetration part 5h Center tube regulation part (Guide tube regulation part) 7 Main body 8 Guide tube 8g Rotation stopper protrusion 8j 2nd engaging part 8k proximal end surface 8m Guide tube body 8n Circular convex part 11 Rotational force input section 11a Flat part 11b Fitting recess 12 Rotating shaft 12a Shaft body 12c Threaded joint 12d Fitting protrusion 12e Spring locking protrusion 13 Middle tube 13a Middle cylinder body 13b Through hole 13c 1st engagement protrusion 13d Proximal end surface 13e First engagement recess 13g sloped surface 14 Outer cylinder 14a External cylinder body 14b Through hole 14c 2nd engagement protrusion 14e Second engagement recess 14g sloped surface 16 Fixing pin 71 Radial Plate Fixation Screw Tool 81 Rotational force input section 81a Flat part 82 Rotating shaft 82a Shaft body 82c Threaded joint 82j 1st engagement part 82k Circular protrusion A Rotation Position B Idle position

Claims

1. A radial fixation plate fixing screw tool for rotating a fixing screw that fixes a radial fixation plate to a radius, comprising: a rotational force input unit to which a rotational force for rotating the fixing screw is input; a rotation shaft portion extending in an axial direction from a tip of the rotational force input portion and rotatable relatively to the rotational force input portion; a center cylinder having a screw coupling portion at a tip end of the rotating shaft portion protruding from the tip end, the center cylinder being disposed outside the rotating shaft portion so as to be movable in the axial direction between a rotating position and an idling position, and the center cylinder having a first engagement projection on an outer circumferential surface; an outer cylinder that is rotatable integrally with the rotational force input portion and has a second engagement protrusion on its inner circumferential surface, the second engagement protrusion being arranged outside the middle cylinder so as to be relatively movable in the axial direction, and being capable of engaging with the first engagement protrusion and rotatable integrally with the middle cylinder when the middle cylinder is located at the rotation position, and being disengaged from the first engagement protrusion and rotatable relative to the middle cylinder when the middle cylinder is located at the idling position; A radial fixation plate fixation screw tool comprising:

2. The rotary shaft further includes a biasing member that biases the center cylinder in the axial direction so that the center cylinder is positioned at the rotation position.

2. The radial fixation plate locking screw tool of claim 1.

3. The screw coupling portion of the rotating shaft portion is a hexalobular screw rotating portion that can be engaged with a hexalobular hole in a head portion of a hexalobular screw serving as the screw.

3. A tool for fixing a radial fixation plate screw according to claim 1 or 2.

4. The rotation shaft portion and the rotational force input portion are configured as separate members.

4. A tool for radial fixation plate fixation screws according to claim 1.

5. A radial fixation plate fixing screw tool for rotating a fixing screw that fixes a radial fixation plate to a radius, comprising: a rotational force input unit to which a rotational force for rotating the fixing screw is input; a rotating shaft portion extending in an axial direction from a tip of the rotational force input portion, being rotatable integrally with the rotational force input portion, the rotating shaft portion having a screw coupling portion at a tip and a first engaging portion on a base end side; a guide tube that is a separate member from the rotating shaft portion, the guide tube being capable of relatively rotating and relatively moving in the axial direction when the rotating shaft portion is inserted, the guide tube being capable of contacting at its tip end with a guide tube regulating portion of a screw insertion hole of the radial fixation plate or a screw insertion hole of a screw guide block placed on the radial fixation plate, and having at its base end a second engaging portion that engages with the first engaging portion; In addition to providing a second rotation stopper portion that can be engaged with a first rotation stopper portion of the screw insertion hole of the screw guide block placed on the radial fixation plate, the second rotation stopper portion being provided on an outer periphery of the guide tube; A third engagement portion is provided on a base end side of the rotating shaft portion, a fourth engaging portion that contacts and engages with the third engaging portion at a base end side of the guide tube to restrict movement of the rotation shaft portion in a screw-in direction, the first engaging portion and the second engaging portion engage with each other, and the third engaging portion and the fourth engaging portion come into contact with each other and engage with each other, thereby restricting the relative rotation between the guide tube and the rotating shaft portion and restricting the movement of the rotating shaft portion in the screwing direction. Tool for radial fixation plate fixation screws.

6. the first engagement portion is a male screw, The second engagement portion is a female screw into which the male screw is screwed.

6. The radial fixation plate locking screw tool of claim 5.

7. The screw coupling portion of the rotating shaft portion is a hexalobular screw rotating portion that can be engaged with a hexalobular hole in a head portion of a hexalobular screw serving as the screw. The radial fixation plate fixing screw tool according to any one of claims 5 to 6.

Images