Wire fixture

Abstract

The present invention achieves a wire fixture to be attached to a medical wire inserted into a bone that is less likely to cause damage to soft tissue such as blood vessels, nerves, and tendons, even when such soft tissue is present in the vicinity of the attachment location. A wire fixture 10 comprises a ball member 11 which is formed in a ball shape and in which a penetration section 12 extending in the thickness direction is formed as a portion through which a medical wire 5 penetrates. In a state in which the medical wire 5 is penetrating the penetration section 12, the ball member 11 is compressed such that the medical wire 5 is pinched by the inner surface of the penetration section 12, thereby attaching the ball member 11 to the medical wire 5.

Description

Wire Fixtures

[0001] The present invention relates to a wire fastener used in the medical field.

[0002] Percutaneous pinning and open reduction and fixation are the most common treatments for fractures. In these treatments, after reduction, Kirschner wires, also known as "K-wires," are inserted into the bone to internally fixate the bone. After treatment, the Kirschner wires may be left straight or bent into an L-shape so that they can be easily removed in an outpatient setting after bone union has been achieved, or they may be bent into an L-shape and buried subcutaneously so that they can be removed through a small incision.

[0003] However, if the insertion side of the Kirschner wire is left straight or bent into an L-shape and exposed to the body surface after treatment, there is a risk that the Kirschner wire will be pushed into the bone from the insertion side, progressing deeper than its original position immediately after insertion. In such cases, there is a risk that the Kirschner wire will be difficult to remove, or that the sharp tip of the Kirschner wire will penetrate the bone and blindly damage the tissue beyond. Furthermore, if the insertion side of the Kirschner wire is bent into an L-shape and exposed to the body surface, there is a risk that the L-shaped portion will get caught and the Kirschner wire will be pulled out. Furthermore, if the insertion side of the Kirschner wire is buried subcutaneously, there is a risk that the Kirschner wire will be pushed inward by force from the outer surface of the skin, and the L-shaped portion will interfere with and damage surrounding soft tissues such as blood vessels, nerves, and tendons.

[0004] Because such problems may occur, it is desirable that the Kirschner wire does not move after treatment. Patent Document 1 describes an internal fixator for fracture treatment used in fracture treatment. This internal fixator for fracture treatment includes a Kirschner wire that is passed through the treatment target site so as to straddle the fracture site, a pair of staplers that hold both ends of the Kirschner wire, and a screw set that fixes both ends of the Kirschner wire on the staplers by mechanical means.

[0005] Patent No. 6616767

[0006] Conventional wire fasteners have many corners in the stapler and bolt set used to fasten medical wires such as Kirschner wires, etc. Therefore, if soft tissue such as blood vessels, nerves, or tendons is present near the stapler and bolt set, the corners of the stapler and bolt set may come into contact with the soft tissue, potentially damaging it.

[0007] The present invention has been made in consideration of the above circumstances, and aims to provide a wire fastener that is attached to a medical wire that is inserted into bone, and that is less likely to damage soft tissue, such as blood vessels, nerves, or tendons, even if soft tissue is present near the attachment point.

[0008] In order to solve the above-mentioned problems, the first invention is a wire fastener that is attached to a medical wire to fix the position of the medical wire as it is inserted into a bone, and includes a ball member that is formed in a ball shape and has a penetration portion that extends in the thickness direction as a portion through which the medical wire passes, and the ball member is attached to the medical wire by crushing the ball member and clamping the medical wire with the inner surface of the penetration portion while the medical wire is passing through the penetration portion.

[0009] In a second aspect of the present invention, in the first aspect, one or more protrusions are formed on the inner surface of the through portion.

[0010] In a third aspect of the present invention, in the first aspect, a pair of concave and convex portions is formed on the inner surface of the through portion in regions that face each other in a front view of the through portion.

[0011] In a fourth aspect of the present invention, in the third aspect, the pair of concave and convex portions are opposed to each other in the short-side direction of the through portion in a front view.

[0012] In a fifth aspect of the present invention, in the first aspect, the ball member has a back surface where one end of the through-hole is open, and a plurality of projections with pointed tips are formed on the back surface.

[0013] In a sixth aspect of the present invention, based on the first aspect, the ball member is formed to have a thickness dimension smaller than the minimum dimension of its outer shape in a front view.

[0014] In a seventh aspect of the present invention, in the sixth aspect, the ball member is formed in an oblate spheroid shape, and the through-hole is a through-hole extending in the minor axis direction.

[0015] In the present invention, the ball member is attached to the medical wire by the simple process of crushing the ball member and clamping the medical wire between the inner surfaces of the penetration portion. Furthermore, even if soft tissue such as blood vessels, nerves, or tendons is present near the location where the ball member is attached, the ball shape of the ball member makes it less likely to damage the soft tissue even when the ball member comes into contact with the soft tissue. According to the present invention, a wire fastener that is attached to a medical wire that is inserted into bone can be realized that is less likely to damage the soft tissue, even if soft tissue is present near the location where the wire fastener is attached.

[0016] Fig. 1(A) is a front view of a ball member of a wire fixture according to this embodiment, as seen from the front side, Fig. 1(B) is a side view of the ball member, and Fig. 1(C) is a front view of a ball member of a different configuration from that of Fig. 1(A). Fig. 2 is a diagram for explaining how to use the wire fixture according to this embodiment, where Fig. 2(A) shows a state in which insertion of a medical wire into a bone is completed, Fig. 2(B) shows a state in which the ball member has been moved to a position in which the ball member contacts the outer surface of the bone, Fig. 2(C) shows the state in which the ball member is being crimped with pliers, and Fig. 2(D) shows the state in which the medical wire is being cut. Fig. 3(A) is a bottom view of a ball member according to a first modification of this embodiment, and Fig. 3(B) is a side view of the ball member. Fig. 4 is a side view of a ball member according to a second modification of this embodiment. Fig. 5 is a perspective view of a ball member according to a third modification of this embodiment. Fig. 6(A) is a front view of the ball member shown in Fig. 5, Fig. 6(B) is a side view of the ball member as seen from below in Fig. 6(A), Fig. 6(C) is a side view of the ball member as seen from the right side in Fig. 6(A), Fig. 6(D) is a cross-sectional view of the ball member taken along the line A-A in Fig. 6(A), and Fig. 6(E) is a cross-sectional view of a ball member at a position corresponding to the line A-A cutting position, in which the direction in which the convex portions are continuously arranged is different from that in Fig. 6(A). Fig. 7 is a view showing a wire fixture according to a fourth modification of this embodiment attached to a medical wire.

[0017] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the following embodiments are merely examples of the present invention and are not intended to limit the scope of the present invention, its applications, or its uses.

[0018] This embodiment is a wire fixation device 10 that is attached to a medical wire 5 (such as a Kirschner wire) in order to fix the position of the medical wire 5 that is inserted into a bone 8. The wire fixation device 10 is used during treatment or surgery such as percutaneous pinning or open reduction and fixation.

[0019] The wire fixture 10 includes one ball-shaped member 11 with a smooth outer surface for one medical wire 5. The material of the ball member 11 is medically acceptable for being embedded under the skin and is a material (stainless steel, titanium, etc.) that undergoes plastic deformation when an external force is applied.

[0020] Here, "spherical" is not limited to a perfect sphere, but refers to a sphere, an ellipsoid, or a similar shape. As shown in Fig. 1, the ball member 11 is formed as a rounded, single piece with no corners except for the edge of the opening of the through-hole 12. The outer periphery of the ball member 11 in a front view is composed only of curves (see Fig. 1(A)), and the outer periphery of the ball member 11 is rounded over its entire length in a cross-sectional view.

[0021] Specifically, the ball member 11 is formed in an oblate spheroid shape. The ball member 11 has a flattened spheroid shape with its minor axis extending in the thickness direction. The minimum dimension L of the ball member 11 in the front view shown in FIG. 1(A) is larger than the thickness dimension D (see FIG. 1(B)). In this embodiment, since the shape of the ball member 11 in the front view is circular, the minimum dimension L of the outer shape is the diameter of the ball member 11. If the shape of the ball member 11 in the front view is vertically elongated, the minimum dimension L of the outer shape is the horizontal dimension (width dimension) perpendicular to the longitudinal direction. For example, the minimum dimension L of the outer shape can be 1.5 times or more the thickness dimension D. In a third modified example described below, the minimum dimension L of the outer shape is 3 times or more the thickness dimension D. By adopting such a shape, if there are substantially flat regions on the front and back surfaces of the ball member 11, the area of ​​the regions will be larger. If there are no substantially flat regions, the area of ​​the regions with small curvature will be larger, thereby increasing the contact area with the bone 8.

[0022] The ball member 11 has a through hole 12 extending in the thickness direction (short axis direction) formed therein as a penetration portion through which the medical wire 5 passes. The ball member 11 has a ring shape (or doughnut shape) due to the through hole 12. The through hole 12 can be, for example, a circular hole. The ball member 11 functions as a hollow rivet. Note that the penetration portion 12 may have an opening on the side surface of the ball member 11, as shown in FIG. 1(C). When viewed from the front, the ball member 11 has a substantially C-shape.

[0023] The dimensions of the ball member 11 are standardized in a number of dimensions so that they can be selected according to the diameter of the medical wire 5. Medical wires 5 generally have a diameter of 0.7 mm to 2.4 mm. The minimum outer dimension (diameter in this embodiment) L of the ball member 11 in a front view can be, for example, 1.5 mm to 8 mm. The thickness D of the ball member 11 can be, for example, 1 mm to 5 mm. The diameter r of the through hole 12 is slightly larger than the diameter of the medical wire 5 and can be, for example, 0.8 mm to 2.8 mm.

[0024] [Method of Using the Wire Fixator] Next, a method of using the wire fixator 10 will be described with reference to Fig. 2. The wire fixator 10 is used after the insertion of the medical wire 5 into the bone 8 has been completed (the state shown in Fig. 2(A)). The following description will be given using an example of open reduction and fixation.

[0025] First, the medical wire 5 is passed through the through-hole 12 of the ball member 11, and as shown in Fig. 2(B), the ball member 11 is moved to a position where the back surface (or front surface) of the ball member 11 contacts the outer surface of the bone 8. Then, in this state, as shown in Fig. 2(C), a tool P such as pliers is used to grasp the side of the ball member 11, and from this state, the ball member 11 is crushed to sandwich the medical wire 5 between the inner surfaces (opposing inner surfaces) of the through-hole 12 (i.e., by crimping the ball member 11), and the ball member 11 is attached (fixed) to the medical wire 5. The ball member 11 serves as a "barb."

[0026] Furthermore, after the ball member 11 is attached, as shown in Figure 2(D), a tool P such as pliers is used to cut the base of the portion of the medical wire 5 that protrudes from the through-hole 12 of the ball member 11. In other words, the medical wire 5 is cut directly above the ball member 11. After this series of steps, the skin is sutured, etc., to complete the surgery. Note that the skin is not shown in Figure 2.

[0027] In the case of the percutaneous pinning method, ball member 11 is attached to medical wire 5 by crushing ball member 11 with a tool P such as pliers at a position where the back (or front) of ball member 11 contacts the outer surface of the skin, thereby pinching medical wire 5 with the inner surface of through-hole 12. Then, medical wire 5 is cut directly above ball member 11, completing the treatment.

[0028] Effects of the Present Embodiment In the present embodiment, the ball member 11 is attached to the medical wire 5 by the simple task of crimping the ball member 11, and the ball member 11 can be easily fixed at the very edge of the insertion site (the position where the ball member 11 contacts the outer surface of the bone 8 or the outer surface of the skin). The ball member 11 fixes the position of the medical wire 5. The medical wire 5 is less likely to shift from its initial insertion position. Furthermore, when the ball member 11 is exposed to the body surface, the medical wire 5 is cut so that the stump of the medical wire 5 barely protrudes from the ball member 11, thereby reducing the risk of the medical wire 5 getting caught on the ball member 11 and being pulled out. According to the present embodiment, it is possible to prevent a decrease in the fixing force for fixing the bone 8 and failure of the fixed bone 8, which are caused by misalignment of the medical wire 5.

[0029] Furthermore, in this embodiment, even if soft tissue such as blood vessels, nerves, or tendons is present near the attachment point of the ball member 11, the ball member 11 is formed in a ball shape, and even if the ball member 11 comes into contact with the soft tissue, damage to the soft tissue is unlikely to occur.

[0030] Here, if the position of the medical wire 5 is not fixed by the ball member 11, there are various concerns as described in the [Background Art] section, and therefore the medical wire 5 may be removed as soon as possible after the bone 8 has healed to a certain extent. In contrast, in this embodiment, there is little risk of the medical wire 5 moving and there are no other concerns, so the bone 8 can be fixed with the medical wire 5 for as long as the bone 8 needs to be fixed.

[0031] [First Modification of the Embodiment] In this modification, as shown in Fig. 3, a plurality of pointed protrusions 15 are formed on the back surface 11b of the ball member 11 (the surface where one end of the through hole 12 opens). The plurality of protrusions 15 are arranged near the through hole 12 and aligned along the circumferential direction of the through hole 12. Each protrusion 15 is formed in a rivet shape. The dimensions of each protrusion 15 may be approximately 1 mm in diameter (diameter of the bottom) and approximately 1 mm in height. The number of protrusions 15 may be, for example, three or more.

[0032] In this modification, the medical wire 5 is passed through the through-hole 12 of the ball member 11 so that the back surface 11b of the ball member 11 faces the bone 8. After the ball member 11 is crimped and attached to the medical wire 5, the ball member 11 is pushed toward the bone 8, and each protrusion 15 is driven into the bone 8.

[0033] Here, when inserting the medical wire 5, the medical wire 5 may bend. In such a case, if the medical wire 5 rotates, the stability of the fixed bone 8 is affected. In this modification, the protrusions 15 prevent the medical wire 5 from rotating. Therefore, the effect on the stability of the fixed bone 8 can be reduced.

[0034] 4, this modification differs from the embodiment in the shape of the ball member 11 in side view. The curvature of the outer periphery 11y on the back side of the ball member 11 is greater than the curvature of the outer periphery 11x on the front side of the ball member 11. Therefore, the contact area of ​​the ball member 11 with the bone 8 is increased.

[0035] [Third Modification of the Embodiment] In this modification, one or more protrusions 21 are provided protruding from the inner surface of the through hole 12 of the ball member 11. In this modification, as shown in Figures 5 and 6(A) to (D), an uneven portion 25 consisting of a plurality of continuous protrusions 21 (for example, three or more protrusions 21) is formed on the inner surface of the through hole 12. Note that in this modification, the through hole 12 may have an opening on the side surface of the ball member 11, as shown in Figure 1(C).

[0036] In a front view of the through hole 12 (ball member 11) shown in Figure 6(A) (viewed in the penetration direction of the through hole 12), each of the convex portions 21 in the uneven portion 25 is formed in a tapered shape (for example, a triangular shape with a base at the base), and the tip of each convex portion 21 is sharp. The uneven portion 25 has a jagged shape. Furthermore, on the inner surface of the through hole 12, each of the convex portions 21 is formed along the penetration direction of the through hole 12 (thickness direction of the ball member 11).

[0037] A pair of concave-convex portions 25 is formed on the inner surface of the through hole 12 in regions facing each other in a front view of the through hole 12. Here, the through hole 12 is formed horizontally elongated in the front view shown in FIG. 6(A). The front shape of the through hole 12 has a longitudinal direction and a lateral direction intersecting the longitudinal direction (for example, a direction perpendicular to the longitudinal direction). The dimension of the lateral direction of the through hole 12 is slightly larger than the diameter of the medical wire 5. The pair of concave-convex portions 25 face each other in the lateral direction of the through portion 12 in a front view.

[0038] When the wire fixture 10 is used, with the medical wire 5 passing through the through hole 12, the ball member 11 is crushed in the short direction of the through hole 12. The medical wire 5 is sandwiched between the pair of uneven portions 25. This makes it difficult for the ball member 11 to become misaligned with respect to the medical wire 5. Note that in the uneven portion 25 of this modified example, the multiple protrusions 21 are continuously aligned in the circumferential direction of the through hole 12, but as shown in FIG. 6(E), the multiple protrusions 21 may also be continuously aligned in the direction of insertion of the through hole 12. In this case, it is difficult for the ball member 11 to become misaligned in the longitudinal direction of the medical wire 5.

[0039] 7 , in this modification, ball members 11 are attached to both the insertion side and the opposite side of the medical wire 5. The wire fixture 10 is provided with two ball members 11 for one medical wire 5. In this modification, the position of the medical wire 5 is fixed more reliably.

[0040] The present invention is applicable to wire fixing devices used in the medical field.

[0041] 5 Medical wire 8 Bone 10 Wire fixing tool 11 Ball member 12 Through hole (through portion)

Claims

1. A wire fastener that is attached to a medical wire in order to fix the position of the medical wire when it is inserted into a bone, the wire fastener comprising a ball member formed in a ball shape and having a penetration portion extending in the thickness direction as a portion through which the medical wire passes, the ball member being crushed with the medical wire passing through the penetration portion to pinch the medical wire with the inner surface of the penetration portion, thereby attaching the ball member to the medical wire.

2. The wire fastener according to claim 1, wherein one or more protrusions are formed on the inner surface of the penetrating portion.

3. A wire fastener as described in claim 1, wherein a pair of projections and recesses are formed on the inner surface of the through-hole in areas opposing each other when viewed from the front of the through-hole (when viewed in the extension direction of the through-hole).

4. The wire fastener according to claim 3, wherein the pair of projections and recesses are opposed to each other in the short direction of the through-hole when viewed from the front.

5. The wire fastener according to claim 1, wherein said ball member has a plurality of projections with sharp tips formed on the rear surface where one end of said penetrating portion opens.

6. The wire fastener according to claim 1, wherein the ball member is formed so that its thickness is smaller than the minimum dimension of its outer shape when viewed from the front.

7. The wire fastener according to claim 6, wherein the ball member is formed in an oblate spheroid shape, and the through-hole is a through-hole extending in the minor axis direction.

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