JP7666334B2 - Guide block for radial fixation plate - Google Patents

Description

The present invention relates to a guide block for a radial fixation plate, which guides a fixation screw that is rotated to fix the radial fixation plate to the radius.

When the radius is fractured, a radius fixation plate is known that spans the fractured portion to immobilize the fractured portion of the radius, instead of a splint (i.e., a splint) or a plaster or FRP cast.

When fixing a radial fixation plate to the radius, multiple fixation screws are screwed into the radius to secure the plate to the radius.

Traditionally, radius fixation plates have been made of thin metal plates such as titanium or its alloys, which are strong, lightweight, and highly biosafe.

However, metal plates do not allow X-rays to pass through, meaning that it is not possible to grasp the condition of the fractured area covered by the radius fixation plate.

Therefore, in recent years, thin plastic radius fixation plates have been developed instead of metal ones (see, for example, Patent Document 1).

Patent Publication No. 4988693

However, when such a resin radius fixation plate is fixed to the radius with fixation screws, the thinness of the radius fixation plate means that the fixation screws cannot be inserted in a specified direction (e.g., perpendicular to the plate surface) into each female screw provided in the radius fixation plate, which may lead to damage to the female screws. In addition, the insertion direction of the fixation screws into the radius fixation plate is designed in advance to match the shape of the radius, so if the fixation screws are inserted in any other direction, even if the female screws are not damaged, it may be difficult for the radius fixation plate to function as a radius fixation plate.

In order to prevent damage to such female threads and to enable the plate to function as a radial fixation plate, a guide block has been placed on the distal region of the radial fixation plate, and the guide block is used to guide the fixation screw so that it can be inserted in a specified direction.

In recent years, it has become necessary to more reliably screw the female threads that secure the plate to the radius into the radius through a cross-threading process, and in order to prevent damage to the female threads and to allow the radius fixation plate to function properly, there has been a demand for a screw tightening guide not only in the distal region of the radius fixation plate, but also in the proximal region of the radius fixation plate.

Therefore, the object of the present invention is to meet the above-mentioned demands and to provide a guide block for a radius fixation plate that can easily and reliably guide the fixation screws when tightening them even in the proximal region of a plastic radius fixation plate.

In order to achieve the above objective, the present invention is configured as follows.

According to one aspect of the present invention, there is provided a guide block for a radial fixation plate, the guide block being placed on a radial fixation plate to guide a fixation screw for fixing the radial fixation plate to a radius, the guide block comprising:
a distal portion that can be mounted on a distal region of the radial fixation plate and has a screw guide hole for the fixation screw that communicates with a screw insertion hole of the radial fixation plate;
a proximal portion that can be placed on a proximal region of the radial fixation plate and has a screw guide hole for the fixation screw that communicates with a screw insertion hole of the radial fixation plate;
The distal portion and the proximal portion are arranged to be movable relative to each other,
A guide block for a radial fixation plate is provided, further comprising a connecting portion disposed between the distal portion and the proximal portion and connecting the distal portion and the proximal portion to allow relative flexibility between the distal portion and the proximal portion .

According to the above aspect of the present invention, the screw guide holes can easily and reliably guide the fixation screws when tightening not only in the distal region of the radius fixation plate but also in the proximal region. Furthermore, even when the proximal region of the radius fixation plate is bent along the radius relative to the distal region of the radius fixation plate and fixed, the proximal portion of the guide block can be made movable relative to the distal portion, for example, can be bent. Therefore, the guide block can be placed so as to be aligned with the bent radius fixation plate, and the screw guide holes can more reliably guide the fixation screws when tightening in both the distal and proximal regions.

These and other objects and features of the present invention will become apparent from the following description of the preferred embodiments taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a perspective view showing a state in which the guide block for a radius fixation plate according to an embodiment of the present invention is used to bend the radius fixation plate with a fixing screw and fix it to the radius, and then the guide block is removed from the radius fixation plate; FIG. 1 is a partially perspective explanatory view showing a state in which a fixing screw is inserted into a guide block and a radial fixation plate by a tool for fixing screws of a radial fixation plate and fastening is started in an embodiment of the present invention; 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. 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, and the tightening is completed. FIG. 2 is a plan view of a radial fixation plate guide block to be placed on the radial fixation plate; 3B is a bottom view of the guide block of FIG. 3B is a side view of the guide block of FIG. FIG. 3B is an explanatory diagram of two locking protrusions of the guide block of FIG. 3A; FIG. 4B is an enlarged cross-sectional view of one locking protrusion of the guide block of FIG. FIG. 3B is a plan view showing a state in which the guide block of FIG. 3A is placed and held on a resin radial bone fixing plate; FIG. 5B is an explanatory diagram showing the position of the metal wire obtained by X-ray photography in the state of FIG. 5A and the position of the radial fixation plate for comparison; A plan view of the guide block placed and held on the resin radial fixation plate on the radius. FIG. 5C is an explanatory diagram showing the position of the metal wire on the radius obtained by X-ray photography in the state of FIG. 5C and the position of the radial fixation plate for comparison. FIG. 1 is a perspective view of the proximal end of a guide block placed and held on a resin radial bone fixing plate on a radius bone, viewed from diagonally above. FIG. 1 is a perspective view of the vicinity of a connecting portion of a guide block placed and held on a resin radial bone fixing plate on a radius bone, as viewed from an obliquely lower side. FIG. 1 is a perspective view of the vicinity of a connecting portion of a guide block placed and held on a resin radial bone fixing plate on a radius bone, as viewed from diagonally above. FIG. 13 is a plan view of a modified example in which the wire arrangement is different, in which the guide block is placed and held on a resin radial bone fixation plate. FIG. 6B is an explanatory diagram showing the position of the metal wire obtained by X-ray photography in the state of FIG. 6A in the modified example of FIG. 6A and the position of the radial fixation plate for comparison; FIG. 6B is an explanatory diagram showing the position of the metal wire obtained by X-ray photography after placing the metal wire on the radius in the state of FIG. 6A in the modified example of FIG. 6A, and the position of the radius fixation plate for comparison; FIG. 6C is an explanatory diagram showing the appropriate line for the radius at the distal end of the radial fixation plate, which is clinically recommended. FIG. 6D is an enlarged view of a portion of FIG. 6D taken perpendicular to the surface of the distal portion of the radial fixation plate; FIG. 13 is a perspective view of a modified example of the arrangement of the distal portion and the proximal portion, in which the guide block is placed and held on a resin radial bone fixing plate; FIG. 7B is a plan view showing a state in which the guide block is placed and held on a resin radial bone fixing plate in the modified example of FIG. 7A; FIG. 7B is a side view of the modified example of FIG. 7A in which the guide block is placed and held on a resin radial bone fixing plate; FIG. 13 is a perspective view of a modified example of the connecting portion between the distal portion and the proximal portion, in which the guide block is placed and held on a resin radial bone fixing plate; FIG. 8B is a side view of the modified example of FIG. 8A in which the guide block is placed and held on a resin radial bone fixing plate; FIG. 8B is an enlarged perspective view of the vicinity of the connecting portion in the modified example of FIG. 8A; FIG. 13 is a perspective view of a state in which a guide block is placed and held on a resin radial bone fixing plate in another modified example of the connecting portion between the distal portion and the proximal portion. FIG. 9B is a side view of the modified example of FIG. 9A in which the guide block is placed and held on a resin radial bone fixing plate; FIG. 9B is an enlarged perspective view of the vicinity of the connecting portion in the modified example of FIG. 9A;

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
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.

The guide block 5 for a radius fixation plate in an embodiment of the present invention is a member that guides the fixation screw 4 when the radius fixation plate 2 is fixed to the radius 3 with the fixation screw 4, as shown in Figures 1 to 2C.

First, we will explain the radial fixation plate 2 and the fixation screw 4, and then we will explain the guide block 5.

As shown in Figures 1 to 2C, the radius fixation plate 2 is fixed to the radius 3 across the fractured portion 3a of the radius 3. At this time, in order to facilitate the screw tightening operation of rotating the fixation screw 4 with the radius fixation plate fixation screw tool 1, a guide block 5 as shown in Figures 3A to 3C is placed on top of the radius fixation plate 2. After being placed in this manner, the guide block 5 is placed on the radius 3, and the screw tightening operation is performed on the radius 3 while guiding the fixation screw 4 in cooperation with a pilot hole previously formed in the radius 3 so that the fixation screw 4 can be inserted in a specified direction using the screw guide 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.

As shown in Figure 1, the fractured portion 3a of the radius 3 is divided into the radius body 3b and the 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.

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

The radial fixation plate 2 is made of, for example, a synthetic resin, such as a thermoplastic resin or a composite material thereof. Examples of thermoplastic resins include PEEK (polyetheretherketone) or polyetherimide.

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

The distal region 2a is fixed to the fracture fragment 3c with a number of fixation screws 4, and the proximal region 2b is fixed to the radial body 3b with a number of fixation screws 4, so that the radial fixation plate 2 straddles the fracture fragment 3a and the fracture fragment 3c is normally connected to the radial body 3b.

The distal region 2a and the proximal region 2b each have a number of circular screw insertion holes 2d extending axially in the thickness direction of the radius fixation plate 2 or in a direction inclined relative 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 Figures 2A to 2C, each screw insertion hole 2d is composed of a large-diameter head storage section 2e and a small-diameter female screw section 2f that is smaller than the inner diameter of the head storage section 2e.

As shown in Figures 2A to 2C, 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.

The shaft portion 4a has a diameter smaller than the inner diameter of the female threaded portion 2f of the screw insertion hole 2d, and is capable of penetrating the female threaded portion 2f. The shaft portion 4a is formed with a main thread 4b that self-taps into the radius 3 after penetrating the screw insertion hole 2d.

As an example, the head 4c has an outer diameter that is the same as the inner diameter of the female threaded portion 2f, and is stored in the head storage portion 2e when the screw is tightened. A sub-thread 4d is formed on the outer peripheral surface of the shaft side of the head 4c, which is screwed into the female threaded portion 2f of the screw insertion hole 2d. Note that instead of a configuration in which the sub-thread 4d is screwed into the female threaded portion 2f, the female threaded portion 2f may be used as a threaded portion without a female thread being formed in advance, and the sub-thread 4d may be used to screw into the threaded portion by performing a self-tapping action.

A hexalobular hole 4j is formed on the top surface of the head 4c, and the screw coupling portion 12c of the rotating shaft portion 12 of the tool 1 described later is coupled thereto, allowing the fixing screw 4 to rotate forward and backward. The hexalobular hole 4j is an example, but the hexalobular hole 4j and the screw coupling portion 12c in the shape of a hexalobular wrench are in contact with each other at the crest and the valley, and are preferable because they 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 screw head by eliminating stress concentration.

As shown in Figures 2A to 2C and 3A to 3C, the guide block 5 is placed and held on the radius fixation plate 2, and then placed on the radius 3. When the fixation screw 4 is then rotated with the radius fixation plate fixation screw tool 1 to perform the screw tightening operation, the guide block 5 guides the fixation screw 4 to make it easier to perform the screw tightening operation.

The guide block 5 may be made of synthetic resin.

As shown in Figures 3A to 3C, the outer shape of the guide block 5 is, for example, 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. As an example, the back surface of the guide block 5 (the surface that contacts the radius fixation plate 2) has a shape that corresponds to the front surface of the radius fixation plate 2 (i.e., the surface opposite to the surface that contacts the radius 3 and that contacts the guide block 5).

The guide block 5 for the radial fixation plate has at least a distal portion 5x and a proximal portion 5y.

The distal portion 5x has a wide shape that can be placed on the distal region 2a of the radius fixation plate 2, and has a plurality of screw guide holes 5d for the fixation screws 4 that communicate with the screw insertion holes 2d of the radius fixation plate 2. When placed on the distal region 2a of the radius fixation plate 2, the distal portion 5x is formed so as to completely cover, almost cover, or partially cover the distal region 2a of the radius fixation plate 2.

The proximal portion 5y has an elongated shape that can be placed on the proximal region 2b of the radius fixation plate 2, and has a plurality of screw guide holes 5d for the fixation screws 4 that communicate with the screw insertion holes 2d of the radius fixation plate 2. When placed on the proximal region 2b of the radius fixation plate 2, the proximal portion 5y is formed so as to completely cover, almost cover, or partially cover the proximal region 2b of the radius fixation plate 2.

Here, in this specification, the "proximal portion" refers to the portion of the guide block 5 that is closer to the heart, similar to the radial fixation plate 2, and the "distal portion" refers to the portion of the guide block 5 that is farther from the heart than the proximal portion.

As an example, the thickness of the guide block 5 is made thicker than the thickness of the radius fixation plate 2 to make it easier to guide the fixation screw 4. In such a case, as an example, the thickness of the radius fixation plate 2 is 2.4 mm, and the thickness of the guide block 5 is about three times that, 6 mm. However, as another example, the thickness of the guide block 5 may be the same or approximately the same as the thickness of the radius fixation plate 2. Even in such a case, the fixation screw 4 can be guided by the thickness of the guide block 5 more than in the case of only the radius fixation plate 2.

In the distal portion 5a and the proximal portion 5b, a large number of circular screw guide holes 5d are formed, each extending in the thickness direction of the guide block 5 or in a direction inclined relative to the thickness direction, in other words, in the thickness direction of the radius fixation plate 2 or in a direction inclined relative to the thickness direction. Each screw guide hole 5d is formed and arranged corresponding to each screw insertion hole 2d. Therefore, in the distal portion 5a, or the proximal portion 5b, or both the distal portion 5a and the proximal portion 5b, a plurality of adjacent screw guide holes 5d can be formed and arranged in a direction that crosses each other obliquely.

As shown in Figures 2A to 2C and 4A, each screw guide 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 tip of the center tube 13 of the tool 1 described later contacts the center tube regulating portion 5h, 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 guide hole 5d beyond the center tube regulating portion 5h, thereby regulating the screw feed depth (i.e., depth). As an example of the position of the center tube regulating portion 5h, it is located at a certain distance (e.g., 5 to 6 mm) from the countersunk surface of the screw insertion hole 2d of the radius fixation plate 2 (i.e., the boundary between the head storage portion 2e and the female thread portion 2f).

The function of each screw guide hole 5d is to guide the axial direction of the fixing screw 4 inserted into the screw insertion hole 2d when tightening the male screw and to regulate the depth of the fixing screw 4, as well as to function as a base for other surgical tools.

The guide block 5 itself, in addition to its function as a support for the fixation screw 4, can also function as a base for inserting various other instruments used during surgery.

When the radius fixation plate 2 is placed on the radius 3, the radius fixation plate 2 also flexes along the radius 3. At this time, the proximal region 2b of the radius fixation plate 2 flexes relatively to the distal region 2a. The distal portion 5x and the proximal portion 5y are arranged to be relatively movable, i.e., relatively flexible, so that the guide block 5 also flexes in response to the flexure of the radius fixation plate 2. An example of such an arrangement is one in which the distal portion 5x and the proximal portion 5y are connected and integrally configured by a connecting portion 20 such as some kind of means or member.

As an example of the connecting portion 20, as shown in Figures 3A to 3C, the distal portion 5x and the proximal portion 5y may be connected by a thin flexible portion 21 so as to be relatively movable. In this case, a groove 22 having at least half the thickness of the guide block 5 is formed between the distal portion 5x and the proximal portion 5y from the front surface side (i.e., the surface opposite to the radius contact surface) of the guide block 5, and a thin flexible portion 21 is formed as the remaining portion on the back surface side. The thickness of the thin flexible portion 21 is, for example, 1/3 of the thickness of the guide block 5. This flexible portion 21 allows the distal portion 5x and the proximal portion 5y to be relatively flexible, and can follow the bending of the radius fixation plate 2. The width dimension of the thin flexible portion 21 is, for example, about the width dimension of the proximal portion 5y.

In addition, the outer peripheral edge of the back surface of the guide block 5 (i.e., the surface facing the radius fixation plate) has at least three retaining claws 5c that can be engaged and held on the outer peripheral edge of the radius fixation plate 2, as shown in Figures 3B and 3C. That is, one retaining claw 5c is arranged on the longitudinal edge of the proximal portion 5y, which is the right end of Figure 3B, and two retaining claws 5c are arranged on the longitudinal edge of the distal portion 5x, which is the left end of Figure 3B, on both edges in the width direction that intersects with the longitudinal direction. By arranging the retaining claws 5c in these three locations, it is possible to hold the plate in a balanced and reliable manner.

4A and 4B, each of the retaining claws 5c has a locking projection 5t that projects in a J-shape or an inverted J-shape in the thickness direction T of the guide block 5. The locking projection 5t projects so as to be securely locked to the boundary between the side surface 2q of the radius fixation plate 2 that is curved outwardly convexly in the transverse direction intersecting with the thickness direction T and the bottom surface 2r that contacts or faces the radius 3. However, the locking projection 5t does not come into contact with the bottom surface 2r that contacts the radius 3 so as not to interfere with the proper positioning of the radius fixation plate 2 and the radius 3.

4B, the locking projection 5t is formed to lock onto the side surface 2q of the radius fixation plate 2 within a range between a first orthogonal line C1 that passes through the lower end position of the radius fixation plate 2 in the thickness direction T of the guide block 5 (i.e., the boundary between the side surface 2q and the bottom surface 2r) and is orthogonal to the thickness direction T of the guide block 5, and a second orthogonal line C2 that passes through the outermost edge of the radius fixation plate 2 and is orthogonal to the thickness direction T of the guide block 5. The reason for this is that if the locking projection 5t protrudes toward the radius 3 side beyond the first orthogonal line C1, the locking projection 5t will be pinched between the radius 3 and the radius fixation plate 2, and the radius 3 and the radius fixation plate 2 will not be properly fixed in position. Furthermore, if the locking projection 5t is positioned on the side opposite the radius 3 from the second orthogonal line C2, it may not be able to exert an locking effect on the radius fixing plate 2, and the plate may not be able to be securely held and fixed.

Therefore, if the locking projection 5t is designed to lock onto the side surface 2q of the radius fixation plate 2 within the range between the first orthogonal line C1 and the second orthogonal line C2, when the radius fixation plate 2 is placed on the radius 3, even if the proximal region 2b of the radius fixation plate 2 bends relative to the distal region 2a, the proximal portion 5y of the guide block 5 can bend relative to the distal portion 5x while remaining engaged and held to the radius fixation plate 2 by the locking projection 5t of the retaining claw 5c, and as a result, the guide block 5 can follow the radius fixation plate 2.

The auxiliary holding claws 5r are arranged on the remaining edge of the guide block 5, except for the connecting portion 20 between the distal portion 5x and the proximal portion 5y. The reason for excluding the connecting portion 20 is to ensure flexibility at the connecting portion 20. It is preferable that the auxiliary holding claws 5r also have a locking protrusion 5t, similar to the holding claws 5c. As an example of the arrangement of the proximal portion 5y of the auxiliary holding claws 5r, in order to more securely hold the proximal portion 5y, they are arranged to face opposing edges along the longitudinal direction of the proximal portion 5y, as shown in FIG. 3B. As an example of the arrangement of the distal portion 5x of the auxiliary holding claws 5r, in order to more securely hold the distal portion 5x, multiple auxiliary holding claws are arranged on the edge along the width direction perpendicular to the longitudinal direction of the distal portion 5x (i.e., the edge between the pair of holding claws 5c of the distal portion 5x) as shown in FIG. 3B.

If the arrangement of the retaining claws 5c on the edge of the guide block 5, or the arrangement of the retaining claws 5c and the auxiliary retaining claws 5r, is symmetrical about the longitudinal central axis of the guide block 5 when viewed from the back side as shown in Figure 3B, a balanced retaining force can be exerted on the radius fixation plate 2.

In this way, when the means for holding the guide block 5 on the radius fixation plate 2 is to insert a screw from the guide block 5 side and screw it into the female thread of the radius fixation plate 2, if the screw tightening work for holding the plate needs to be redone or if the screw tightening work itself fails, the female thread of the plastic radius fixation plate 2 will be damaged and the radius fixation plate 2 will need to be removed from the radius 3 and discarded, which is cumbersome and involves problems such as prolonging the surgery time. In contrast, if the holding claws 5c or the holding claws 5c and the auxiliary holding claws 5r are used, the holding force of the claws can be released and the operation can be redone any number of times without damaging the plastic radius fixation plate 2.

As shown in Figs. 3A to 3C, a removal groove 5q is formed at one end edge of the proximal portion 5y, for example, by a rectangular notch. The removal groove 5q is formed so that the boundary between the radius fixation plate 2 and the guide block 5 is exposed. Therefore, by inserting, for example, a raspatrium or a spatula into this removal groove 5q and inserting it into the boundary between the radius fixation plate 2 and the guide block 5 and twisting it so as to separate the radius fixation plate 2 and the guide block 5, it is possible to start releasing the holding force of each of the holding claws 5c and each of the auxiliary holding claws 5r near the removal groove 5q. Then, by inserting a raspatrium or a spatula into the boundary between the radius fixation plate 2 and the guide block 5 in the remaining portion, or by removing the guide block 5 from the radius fixation plate 2 by hand, it is possible to release the holding force of the other holding claws 5c and auxiliary holding claws 5r and to detach and remove the guide block 5 from the radius fixation plate 2.

Furthermore, as shown in Figures 3C and 5A to 5G, metal wires 19, as an example of linear markers, are arranged around the entire outer edges of the distal portion 5x and the proximal portion 5y. This is for the following reason. When the fractured portion is photographed with an X-ray, if the radius fixation plate 2 is made of resin, the radius fixation plate 2 itself is not visible in the X-ray and its position cannot be confirmed. For this reason, if an X-ray is taken while a guide block 5 (see Figures 5A to 5B) having metal wires 19 around its entire edge is placed and held on the resin radius fixation plate 2, the metal wires 19 on the entire edge of the guide block 5 will be visible, and the position of the radius fixation plate 2 can be confirmed based on the visible metal wires 19 (see Figures 5C to 5G).

Figure 5A is a diagram of the guide block 5 placed and held on the resin radius fixation plate 2. Figure 5B is an explanatory diagram showing the position of the metal wire 19 obtained by X-ray photography in the state of Figure 5A, and the position of the radius fixation plate 2 for comparison. Figure 5C is a diagram of the guide block 5 placed and held on the resin radius fixation plate 2 on the radius 3. Figure 5D is an explanatory diagram showing the position of the metal wire 19 obtained by X-ray photography on the radius 3 in the state of Figure 5C, and the position of the radius fixation plate 2 for comparison. Figures 5E to 5G are perspective views of the guide block 5 placed and held on the resin radius fixation plate 2 on the radius 3, viewed from different angles.

Such wires 19 may be placed in the radial fixation plate 2 instead of the guide block 5, if necessary.

The wire 19 may be disposed not only around the entire edge of the guide block 5, but also on a part of the edge of the guide block 5. For example, the wire may be disposed at least at one edge protruding along the width direction of the distal portion 5x and at two edges extending along the longitudinal direction of the proximal portion 5y, as shown in Figs. 6A to 6E. At least one protruding edge of the distal portion 5x means, for example, the edge portion 19a (hereinafter referred to as the first marker 19a) that protrudes most to the right side in the width direction (i.e., the ulnar side) in the case of the left hand radius fixation plate 2 shown in Figs. 6A to 6B. This means that in the case of the left hand radius fixation plate 2, if the radius fixation plate 2 protrudes too far to the right side (ulnar side) of Fig. 6B or 6C, the radioulnar joint, which controls the rotation of the hand, will malfunction, and the hand will not be able to rotate. Therefore, in order to avoid such a situation, it is necessary that the position of the ulnar side of the distal portion 2a of the radius fixation plate 2 can be confirmed by the first marker 19a.

At this time, it is clinically recommended that the distal end 2a of the radius fixation plate 2 be placed so as not to exceed the appropriate line D1 of the radius 3, as shown in Figures 6D and 6E. In Figure 6D, due to the angle at which the radius fixation plate 2 is viewed, the first marker 19a appears to be more proximal than the most distal position, but when observed from a direction perpendicular to that portion, as shown in Figure 6E, it can be seen that the first marker 19a indicates the most distal line. The first marker 19a is necessary for this confirmation as well.

In addition, a pair of second markers 19b parallel to the longitudinal direction of the guide block 5 are also required to check the longitudinal inclination of the radius fixation plate 2 relative to the longitudinal direction of the radius 3.

In this way, by using the second marker 19b in combination with the first marker 19a on the distal ulnar side, if the photographer or operator understands the shape of the radius fixation plate 2 in advance, it is possible to grasp where all edges of the radius fixation plate 2 are located on the radius 3 by aligning the positions of the first marker 19a and the second marker 19b. Note that if the longitudinal edge of the proximal region 2bb is about the same length as the radius fixation plate, there is almost no possibility of it interfering with the region where high-risk tissue is located, and grasping the position is not essential, so the placement of a marker is omitted. However, if confirmation is required, a marker may be placed on the longitudinal edge of the proximal portion 5y on the opposite side to the distal portion 5x.

Below, an example of a tool for rotating the fixing screw 4 is described to explain the guidance and depth regulation of the fixing screw 4, but the tool is not limited to the configuration below.

2A to 2C, 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 center cylinder 13, and an outer cylinder 14, and as an example, may be made entirely of metal, or the center cylinder 13 and the outer cylinder 14 may be made of synthetic resin and the remaining portions may be made of metal. The tool 1 for fixing a radial fixation plate screw may further include a biasing member 15.

The rotational force input unit 11 is a part that applies a rotational force around the 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 the flat surface portion 11a and the curved back surface portion of the flat surface portion 11a may be pinched with the fingers to enable the tool 1 to rotate forward and backward around the axis. The flat surface portion 11a is not necessarily required for the rotational force input unit 11, as long as it can rotate forward and backward around the axis to tighten and loosen the fixing screw 4.

The rotating shaft portion 12 has a screw connection portion 12c at the tip of the shaft body 12a which is arranged coaxially with the rotational force input portion 11 and connected so as to be capable of rotating relative to the shaft body 12a, and a ring-shaped spring locking projection 12e which protrudes radially beyond the outer diameter of the shaft body 12a near the base end of the shaft body 12a.

The screw coupling portion 12c is a hexalobular screw rotation portion that is disposed at the tip of the shaft body 12a and can be coupled to the hexalobular hole 4j of the head 4c of the fixing screw 4 so as not to rotate relative to the hexalobular screw, and allows the fixing screw 4 to rotate forward and backward in order to tighten or loosen 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 the hexalobular screw 4 is used as the fixing screw 4.

The middle tube 13 is made of a cylindrical member.

The middle tube 13 comprises a middle tube main body 13a and a first engagement protrusion 13c protruding radially from the outer peripheral surface of the base end of the middle tube main body 13a.

The middle tube body 13a is arranged on the outer peripheral surface of the base end side of the hexagonal cross-section shaft body 12a of the rotating shaft section 12, and has a through hole with a hexagonal cross-section, which is an example of a part that cannot rotate around the axis relative to the hexagonal cross-section shaft body 12a (in other words, can rotate integrally with it) and can move in the axial direction between rotation position A and idling position B.

The screw connection portion 12c at the tip of the rotating shaft portion 12 always protrudes from the tip of the middle tube body 13a.

Near 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 protrusion 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 rather than the idling position B. However, the coil spring 15 is not necessarily required. For example, in a tool 1 with a simple configuration, the coil spring 15 can be omitted, and the middle tube 13 can be returned to the initial position, the rotation position A, by hand every time the fixing screw 4 is tightened, and the middle tube 13 can be used while being careful not to move the middle tube 13 when tightening the fixing screw. Even in such a case, the above-mentioned idling operation can be performed at the idling position B.

As an example, the first engagement protrusion 13c is formed as one or more circumferentially curved plates with trapezoidal cross sections in the radial direction. For example, four first engagement protrusions 13c are formed at predetermined intervals, for example, at 90 degree intervals. In the figure, the first engagement protrusions 13c are simplified to be gear-shaped.

The outer tube 14 is composed of a cylindrical member having a tapered shape and a larger diameter than the inner tube 13.

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

The through hole of the outer tube 14 has a large inner diameter at the base end and gradually becomes smaller in diameter toward the tip, so that the middle tube 13 cannot come off the outer tube 14 in the axial direction toward the tip.

The outer cylinder 14 is arranged 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 end portion of the rotational force input portion 11. Furthermore, a fixing pin (not shown) is inserted diametrically into the tip end portion of the rotational force input portion 11 and the base end portion of the outer cylinder 14 to fix the tip end portion of the rotational force input portion 11 and the base end portion of the outer cylinder 14. Therefore, the rotational force input portion 11 and the outer cylinder 14 rotate forward and backward as a unit.

The second engagement protrusions 14c of the outer cylinder 14 are formed, for example, in the shape of one or more plates in the circumferential direction with a trapezoidal cross section curved in the radial direction. For example, the second engagement protrusions 14c are formed at predetermined intervals, for example, four at intervals of 90 degrees. In the figure, the second engagement protrusions 14c are also shown simplified as gears.

Therefore, the first engagement protrusion 13c can move axially back and forth between a rotational position A where they are engaged with the second engagement protrusion 14c, and an idling position B where they are disengaged. That is, in the rotational position A, the first engagement protrusion 13c and the second engagement protrusion 14c are engaged around the axis, and cannot rotate relatively around the axis. In the idling position B, the engagement between the first engagement protrusion 13c and the second engagement protrusion 14c around the axis is released, and they can rotate relatively around the axis.

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 located at rotation position A.

Tool 1 having such a configuration can be used as follows.

First, the guide block 5 is placed on the radius fixation plate 2 and held by the holding claws 5c or the holding claws 5c and the auxiliary holding claws 5r. Then, as shown in Figures 2A and 5C, 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.

2A, the fixing screw 4 is inserted into one of the screw guide holes 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 guide hole 5d, the fixing screw 4, and the tool 1 are held coaxially with each other.

Next, the rotational force input unit 11 of the tool 1 is started to rotate in the direction of tightening 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 rotating shaft 12, and the fixing screw 4, and the fixing screw 4 is screwed into the radius 3 while being guided by the screw guide 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 around the axis between the first engagement protrusion 13c and the second engagement protrusion 14c. At this time, the screw guide hole 5d of the guide block 5 guides the fixing screw 4 so that it advances smoothly in its axial direction, and the shaft 4a of the fixing screw 4 begins to be screwed into the radius 3. When the fixing screw 4 is screwed in, the main thread 4b of the shaft 4a of the fixing screw 4 performs a self-tapping action on the radius 3 and is screwed in.

2B, as the rotation of the fixing screw 4 in the tightening direction progresses and the fixing screw 4 is screwed into the radius 3, the center tube 13 advances within the center tube guide portion 5e of the screw guide hole 5d, and the center tube 13 comes into contact with the center tube regulating portion 5h. As the rotation in the tightening direction continues even after the contact, the fixing screw 4 is further screwed into the radius 3 and advances in the axial direction, and the center tube 13 begins to retreat relative to the rotating shaft portion 12. This means that the center tube 13 begins to move from the rotation position A toward the idling position B. At this time, as an example, the sub-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, and the radius fixation plate 2 is appropriately held in position and fixed, such as by being in close contact with the radius 3.

As a result, as shown in FIG. 2C, the fixing screw 4 is positioned at a predetermined position (i.e., the fixing screw tightening position) relative to the radial 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 radial 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 positioned at 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, a position that is inserted into the female thread section 2f side from the countersunk surface. When the fixing screw 4 is positioned at such a predetermined position, if the tool 1 moves the middle 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.

When releasing the tightening, 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 the guide block.

According to the above embodiment, the screw guide hole 5d can easily and reliably guide the fixation screw 4 when tightening not only in the distal region 2a of the radius fixation plate 2 but also in the proximal region 2b. In addition, even when the proximal region 2b of the radius fixation plate 2 is bent along the radius 3 relative to the distal region 2a of the radius fixation plate 2 and fixed, the proximal portion 5y of the guide block 5 can be made relatively movable, for example, bent, relative to the distal portion 5x of the guide block 5. Therefore, the guide block 5 can be placed so as to be aligned with the bent radius fixation plate 2, and the screw guide hole 5d can more reliably guide the fixation screw 4 when tightening in both the distal region 2a and the proximal region 2b. If the proximal region 2b cannot be bent along the radius 3 relative to the distal region 2a as described above, the guide block 5 may not be aligned with the radius fixation plate 2 and may partially float or come off the radius fixation plate 2.

In addition, according to the embodiment, the distal portion 5x and the proximal portion 5y are connected by the thin flexible portion 21, so that the distal portion 5x and the proximal portion 5y can be handled as one set, which is easy to handle during surgery, and prevents mistakes in assembling when selecting an appropriate guide block 5 from multiple guide blocks 5 of different sizes, etc. Furthermore, the thin flexible portion 21 can be formed in the guide block 5 simply by forming the groove 22, making it easy to manufacture.

The present invention is not limited to the above-described embodiments and can be implemented in various other forms.

As a modified example of the arrangement of the distal portion 5x and the proximal portion 5y, as shown in Figures 7A to 7C, the distal portion 5x and the proximal portion 5y may be configured as completely separate members, and the distal portion 5x and the proximal portion 5y may be arranged with a gap 25 therebetween. With this arrangement, the distal portion 5x and the proximal portion 5y can be configured to be relatively movable.

As another modification of the connecting portion 20, it is not limited to the thin flexible portion 21, but may be a hinge connecting portion 26 as shown in Figs. 8A to 8C. This hinge connecting portion 26 includes a first connecting member 26a having a pair of bifurcated branch portions 26e, a second connecting member 26d interposed between the pair of branch portions 26e, and a pivot pin 26c connecting the branch portion 26e and the second connecting member 26d so as to be rotatable relative to each other. The first connecting member 26a is supported by the distal portion 5x and the second connecting member 26d is supported by the proximal portion 5y, but conversely, the first connecting member 26a may be supported by the proximal portion 5y and the second connecting member 26d may be supported by the distal portion 5x. The pivot pin 26c is disposed along a lateral direction perpendicular to the thickness direction of the guide block 5, and the second connecting member 26d is allowed to rotate relatively to the first connecting member 26a around the imaginary rotation axis, so that the proximal portion 5y can bend relative to the distal portion 5x. In this example, the second connecting member 26d can rotate to any angle relative to the first connecting member 26a around the imaginary rotation axis.

As yet another modified example of the connecting portion 20, instead of being limited to the thin flexible portion 21, as shown in Figures 9A to 9C, it may be a thin sheet 27 that is stretched between the distal portion 5x and the proximal portion 5y on the surface side of the guide block 5. This thin sheet 27 allows the proximal portion 5y to bend relative to the distal portion 5x.

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.

The guide block for a radius fixation plate according to the above aspect of the present invention can easily and reliably guide the fixation screw of a plastic radius fixation plate when screwing it in.

1 Tool for fixing screws of radial fixation plate 2 Radial fixation plate 2a Distal region 2b Proximal region 2d Screw insertion hole 2e Head storage portion 2f Female thread portion 2q Side surface 2r Bottom surface 3 Radius 3a Fracture portion 3b Radius body 3c Fracture fragment 4 Fixation screw 4a Shaft portion 4b Main screw 4c Head portion 4d Sub-screw 4j Hexalobular hole 5 Guide block 5a Distal portion 5b Proximal portion 5c Retaining claw 5d Screw guide hole 5e Center tube guide portion 5f Rotating shaft portion through portion 5h Center tube regulating portion 5q Release groove 5r Auxiliary retaining claw 5t Engagement protrusion 5x Distal portion 5y Proximal portion 11 Rotational force input portion 11a Planar portion 12 Rotating shaft portion 12a Shaft body 12c Screw coupling portion 12e Spring engagement protrusion 13 Center tube 13a Middle tube body 13c First engagement protrusion 13d Base end surface 14 Outer tube 14a Outer tube body 14c Second engagement protrusion 19 Marker 19a First marker 19b Second marker 20 Connecting portion 21 Thin-walled flexible portion 22 Groove 25 Gap 26 Hinge coupling portion 26a First connecting member 26c Rotation pin 26d Second connecting member 26e Branching portion A Rotation position B Idle position C1 First orthogonal line C2 Second orthogonal line D1 Appropriate line of radius

Claims (5)

A guide block for a radial fixation plate, which is placed on the radial fixation plate to guide a fixation screw for fixing the radial fixation plate to a radius,
a distal portion that can be mounted on a distal region of the radial fixation plate and has a screw guide hole for the fixation screw that communicates with a screw insertion hole of the radial fixation plate;
a proximal portion that can be placed on a proximal region of the radial fixation plate and has a screw guide hole for the fixation screw that communicates with a screw insertion hole of the radial fixation plate;
The distal portion and the proximal portion are arranged to be movable relative to each other,
The distal end of the proximal portion is provided with a connecting portion that is disposed between the distal end and the proximal portion and connects the distal end and the proximal portion to each other so as to be relatively flexible between the distal end and the proximal portion.
Guide block for radial fixation plates. a first retaining claw disposed at at least two locations on an end edge of the distal portion and configured to retain the distal portion in position when placed on the distal region of the radial fixation plate;
and a second retaining claw disposed at at least one end edge of the proximal portion for retaining the proximal portion in a position when placed on the proximal region of the radial fixation plate.
2. The guide block for a radial fixation plate according to claim 1 . and further comprising linear markers arranged at least at one location on a distal end edge of the distal portion and at least two locations on a pair of opposing end edges extending along a longitudinal direction of the proximal portion to indicate a position of the guide block for the radial fixation plate .
The guide block for a radius fixation plate according to any one of claims 1 to 2 . The linear marker is a wire disposed around the entire outer edge of each of the distal portion and the proximal portion.
4. The guide block for a radial bone fixation plate according to claim 3 . The distal portion and the proximal portion are made of resin.
The guide block for a radius fixation plate according to any one of claims 1 to 4 .

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