JP5631722B2 - Medical linear members - Google Patents

Description

  The present invention relates to a medical linear member, and in particular, to a fractured portion that is bound using a contraction force with respect to a length direction and an expansion force with respect to a diameter direction accumulated in the stretched medical linear member. The present invention relates to a medical linear member capable of applying a predetermined packing pressure in the inner direction from the outer periphery.

In the general healing process of fractures, blood that has bleed from the bone marrow of the fractures accumulates in the gaps between the bones, and the solidified blood is replaced with fibrous cells as the day passes, among which bone cells and chondrocyte system Fractures are healed when cells form and the fractures are connected by callus.
When surgery is needed to treat a fracture, first reduce the broken bone accurately to return the bone to its original shape and length, then expose the affected area and then use a special instrument to reduce the bone. The bone fragment is firmly fixed by a binding means such as a metal wire or a fixing means such as a pin, bolt, rod or plate.

On the other hand, in surgery for fracture treatment of children whose bone strength is lower than that of adults and bones are in the process of growth, if the binding force of the binding means such as a metal wire that fixes the fracture is too strong, bone growth may be hindered. May be damaged. Therefore, in the treatment of fractures in children, treatment with casts or towing is often selected rather than surgery, but healing may proceed in a state where the bone is displaced.
Also, in surgery for fracture treatment of elderly people and osteoporosis patients with insufficient bone mass and bone quality, there is a risk of damaging the bone if the binding force of the binding means such as a metal wire that fixes the fracture is too strong. However, if the binding force of the binding means is weak, fixation of the fractured part may be insufficient and the healing process may be adversely affected.
Patent Document 1 discloses a fastening cable for fixing a fractured part or binding a prosthesis to a bone.
In Patent Document 2, a plurality of fine metal wires are twisted to form a twisted layer on the outer surface of a core material obtained by twisting two metal fine wires, and a spiral is formed between the twisted layer and the core material. A metal stranded wire having a stretchable portion extending in a shape is disclosed.

Japanese Patent Laid-Open No. 7-163583 Japanese Patent Laid-Open No. 5-30884

However, since the fastening cable of Patent Document 1 is formed by simply twisting metal wires such as stainless steel and titanium, the tensile strength is high, and the stretchability and the flexibility are low. Only the binding force worked.
The metal stranded wire of Patent Document 2 has a cross-sectional deformability, but has a high tensile strength and poor stretchability. Therefore, even if it is used as a wire for fixing a fractured part, the binding force when the fractured part is bound Only a slight restoring force was applied to return to the original cross-sectional shape.
The present invention has been made in view of the above points, with the aim of constantly applying a predetermined capsule pressure in the inner direction from the outer periphery to the bound fractured part, while maintaining the tensile strength and flexibility, It is an object of the present invention to provide a medical linear member that can use the contraction force in the length direction and the expansion force in the diameter direction accumulated in the stretched medical linear member as the envelope pressure.

The medical linear member of the present invention has the following characteristics.
According to a first configuration of the present invention, a basic body in which a plurality of wires are arranged is a spiral body that has a space inside and is spirally wound with a gap in the axial direction, and the outer periphery of the spiral body is coated with a resin. The medical linear member is covered with a layer.
With the above-described configuration, the medical linear member of the present invention has a coil spring characteristic, and while maintaining the tensile strength and the flexibility, the elastic force in the length direction is imparted to the contraction force from the stretched state and the diameter direction. An enveloping force is always applied to the fractured portion that is bound by the medical linear member of the present invention, and a wrapping pressure composed of a contracting force and an expanding force is always applied.
In addition, by covering the outer periphery of the spiral body as a medical linear member with a resin coating layer, the resin coating layer is deformed according to the expansion and contraction or bending of the medical linear member, so that the outer surface of the medical linear member is slippery. Will improve.

As said wire, the thing of various cross-sectional shapes can be used, For example, a substantially circular thing can be used.
As the wire for the wire in the present invention, a material such as metal, plastic, rubber, or ceramic can be used, and a material approved by the Pharmaceutical Affairs Law or the like for medical use is preferable. In order to ensure the tensile strength, stretchability, bendability, and recoverability of the medical linear member 10, it is preferable to form the wire 11 with a spring material having a large elastic force. Examples of the metal include stainless steel such as SUS316, titanium alloy, Co—Cr alloy, non-ferrous metal, piano wire metal, and the like. In particular, Ni-free metal not containing nickel is preferable. . Specifically, titanium alloy standardized by ASTM F-136 (component blending weight ratio is as follows. Nitrogen (N) 0.05% or less, carbon (C) 0.08% or less, hydrogen (H) 0.012% or less, iron (Fe) 0.25% or less, oxygen (O) 0.13% or less, aluminum (Al) 5.5 to 6.5%, vanadium (V) 3.5 to 4.5%, titanium (Ti) balance, 100% in total) and the like. Moreover, it is preferable to use a superelastic material as the metal of the spring material, whereby the medical linear member 10 having a large tensile strength, stretchability, flexibility, and recoverability can be formed. As such a superelastic material, a shape memory alloy made of a titanium alloy containing titanium, a nickel alloy containing nickel, a nickel titanium alloy containing both titanium and nickel, or the like can be used.
In the present invention, by using the shape memory alloy, the medical linear member can be contracted and tightened by utilizing the property of returning to the original shape stored at a predetermined temperature. In this case, for example, after the medical linear member is wound around a predetermined part such as a fractured part while being plastically deformed at room temperature, the medical linear member is contracted and tightened at a temperature such as body temperature or hot water. it can.
In selecting the resin coating layer, biocompatibility is considered in addition to flexibility and extensibility. As the resin coating layer, an electron beam cross-linked soft polyolefin resin using polyethylene as a main raw material is also suitable. However, when a fluororesin is selected as the resin coating layer, the fluororesin is excellent in slipperiness, so Surface slipperiness is greatly improved. As the fluororesin coating layer, polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride ( Preferably, the resin coating includes at least one selected from the group consisting of PVF), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and tetrafluoroethylene-ethylene copolymer (PETFE).
The method for forming the coating layer is not particularly limited. For example, the helical body can be inserted into a tubular resin body such as a heat-shrinkable tube, and the tubular resin body can be contracted by heating. Alternatively, the spiral body may be simply inserted into a non-shrinkable tubular resin body, or the resin is applied by passing the spiral body through a resin whose viscosity is reduced by heating and melting, and then cooled on the outer periphery of the spiral body. The resin coating layer can be formed. Furthermore, the resin coating layer can be formed on the outer periphery of the spiral body by removing the solvent after passing the spiral body through the resin liquid dissolved in the solvent and applying the resin liquid.

The second configuration of the present invention is characterized in that it is a medical linear member having an auxiliary core made of one or more wires formed in a bent shape in at least a part of the space portion of the first configuration.
If an auxiliary core is provided, the tensile strength of the medical linear member can be improved while securing extensibility, contractibility, and flexibility. The length of the auxiliary core is the elastic limit value of the medical linear member having a coil spring characteristic so that the medical linear member does not extend beyond the elastic limit value (1+ (elastic limit elongation rate)). Is set to a length that takes into account It can be set so that (length of auxiliary core) <(length of linear member for medical use) × (elastic limit value). The elastic limit value of the medical linear member is the stress at the boundary of whether or not permanent deformation is caused by applying a repeated load. When the surgeon extends the medical linear member, only the pulling force of the medical linear member acts at first. However, when the auxiliary core is extended, the pulling force of the auxiliary core is applied. It can be notified that the elastic limit value of the member is close. As the bent shape of the auxiliary core, any one selected from a zigzag shape, a wave shape, a spiral shape, etc., or a combination of two or more shapes can be adopted, and a partial section may be a straight line along the axis. Is possible.
The third configuration of the present invention is characterized in that all or part of the wires of the basic body in the first configuration to the second configuration are medical linear members made of metal.
A fourth configuration of the present invention is characterized in that a medical linear member in which metal plating is applied to at least a part of the basic body or the resin coating layer in the first configuration to the third configuration.

According to the medical linear member of the present invention, while maintaining the tensile strength and flexibility, the contraction force from the stretched state and the expansion force in the diametrical direction are imparted by imparting stretchability to the length direction, A capsule pressure composed of a contraction force and an expansion force always acts on the fractured portion that is bound by the stretched medical linear member.
Therefore, it is difficult to cause damage to the fracture due to excessive binding force, and it can be widely applied not only to healthy adults but also to children and elderly people with weak bone strength.
Further, the medical linear member of the present invention can be combined with an external fixing means such as a cast to expand the options for a fracture treatment method.
In addition, since the slipperiness of the outer surface of the medical linear member is improved by coating the outer periphery of the spiral body with the resin coating layer, the sliding between the body tissue and the medical linear member due to body movement or pulsation after surgery is performed. Since the dynamic resistance can be suppressed low, there is little adverse effect on the body tissues other than the treatment target site.

1 is an external view showing a medical linear member of Example 1. FIG. It is explanatory drawing which shows the expansion | extension process of the medical linear member of Example 1. FIG. It is explanatory drawing which shows the tight binding state of the fracture site | part using the medical linear member of Example 1. FIG. 6 is an external view showing a medical linear member of Example 2. FIG. It is explanatory drawing which shows the expansion | extension process of the medical linear member of Example 2. FIG. It is explanatory drawing which shows the tight binding state of the fracture site | part using the medical linear member of Example 2. FIG.

DESCRIPTION OF SYMBOLS 10 Medical linear member 11 Wire 12 Basic body 13 Space part 14 Auxiliary core 15 Resin coating layer D1 Outer diameter P1 Pitch S1 Space | gap part

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the scope of application of the medical linear member of the present invention is not limited by the present embodiment.

[Example 1]
1A and 1B are external views showing a linear member of Example 1, FIG. 1A is a front view, and FIG. 1B is an end view taken along the line I-I shown in FIG. FIG. 2 is an explanatory diagram illustrating an extension process of the linear member of the first embodiment. FIG. 3 is an explanatory view showing a tight state of a fractured portion using the medical linear member 10 of the first embodiment.
The medical linear member 10 of Example 1 is a spiral body in which a plurality of wires 11 are arranged to form a basic body 12, and the basic body 12 is spirally wound with an outer diameter D1 across the gap S1 in the axial direction. The spiral body has a space portion 13 along the axial direction.
Here, the diameter of the space portion 13 and the size of the gap portion S1 can be appropriately set according to the purpose of use of the medical linear member 10 or the like.
Furthermore, the outer periphery of the spiral body is covered with a resin coating layer 15 made of tetrafluoroethylene-hexafluoropropylene copolymer (FEP).

Hereinafter, the medical linear member 10 according to the first embodiment will be described as a surgical fastening cable when the wound portion is wound around a fractured portion and fixed.
When a tensile force F1 is applied to both ends of the medical linear member 10 (the lower end side is omitted in FIG. 2) in the length direction, the inclination angle of the spiral is increased, the pitch P1 is increased, and P1 ′ is extended. At the same time, the dimension of the gap S1 decreases to S1 ′, and the outer diameter D1 contracts to the outer diameter D1 ′. At this time, the medical linear member 10 is in a state of accumulating a contraction force f1a that tries to return to the pitch P1 before expansion and an expansion force f1b that tries to return to the outer diameter D1.
If the pulling force F <b> 1 with respect to the medical linear member 10 is released, it is possible to return from the stretched state to the original state due to the spring property of the medical linear member 10.
The surgeon wraps the medical linear member 10 around the fractured portion C, applies a tensile force F1 to extend the medical linear member 10 in the length direction, and the fractured portion C is stretched with the expanded medical linear member 10. It is fixed by fastening.

[Operation of Example 1]
The fractured part C fixed by the medical linear member 10 has a wrapping pressure composed of a contraction force f1a that tries to return to the pitch P1 before expansion and the dimension S1 of the gap, and an expansion force f1b that tries to return to the outer diameter D1. Will always act from the outer periphery of the fractured part C toward the center side.
In addition, since the medical linear member 10 is wound around the fractured part C, the cross-sectional shape is deformed from a substantially circular shape to a flat elliptical shape, so that the contact of the medical linear member 10 with the fractured part C becomes surface contact. The fixed state of the fractured part C is stabilized and a restoring force for returning to the substantially circular cross-sectional shape always acts toward the center side of the fractured part C.
Moreover, since the slipperiness of the outer surface of the medical linear member 10 improves by coat | covering the outer periphery of a helical body with the resin coating layer 15, the internal tissue and the medical linear member 10 by the body movement and pulsation after a surgery are improved. Therefore, adverse effects on the body tissue other than the treatment target site can be reduced.

[Example 2]
4A and 4B are external views showing the medical linear member of Example 2. FIG. 4A is a front view, and FIG. 4B is an end view taken along the line I-I shown in FIG. FIG. 5 is an explanatory view showing the extension process of the linear member of the second embodiment. FIG. 6 is an explanatory diagram showing a tightly bound state of a fractured portion using the medical linear member 10 of the second embodiment.
In Example 2, an auxiliary core 14 formed by bending a wire into a wave shape is inserted into the space 13 of the medical linear member 10 of Example 1, and the length of the auxiliary core 14 is the elastic limit value of the medical linear member 10. Set to a length that does not extend beyond. Since the configuration other than the auxiliary core 14 is the same as that of the first embodiment, detailed description thereof is omitted.

Hereinafter, the medical linear member 10 according to the second embodiment will be described as a surgical fastening cable when being wound around a fractured portion and fastened and fixed.
When a tensile force F1 is applied to both ends of the medical linear member 10 (the lower end side is omitted in FIG. 4) in the length direction, the inclination angle of the spiral is increased, the pitch P1 is increased, and P1 ′ is extended. At the same time, the dimension of the gap S1 decreases to S1 ′, and the outer diameter D1 contracts to the outer diameter D1 ′. At this time, the medical linear member 10 is in a state of accumulating a contraction force f1a that tries to return to the pitch P1 before expansion and an expansion force f1b that tries to return to the outer diameter D1.
If the pulling force F <b> 1 with respect to the medical linear member 10 is released, it is possible to return from the stretched state to the original state due to the spring property of the medical linear member 10.
The surgeon wraps the medical linear member 10 around the fractured portion C, applies a tensile force F1 to extend the medical linear member 10 in the length direction, and the fractured portion C is stretched with the expanded medical linear member 10. It is fixed by fastening.
When the surgeon extends the medical linear member, only the pulling force of the medical linear member acts at first. However, when the auxiliary core is extended, the pulling force of the auxiliary core is applied. It can be notified that the elastic limit value of the member is close.
By providing the auxiliary core 14, the elastic limit value of the medical linear member 10 can be set while securing extensibility, contractibility, and flexibility, and it can contribute to improvement in tensile strength and prevention of breakage.
That is, when the surgeon wraps the medical linear member 10 around the fractured part C and applies the tensile force F1 to extend the medical linear member 10 in the length direction, the surgeon is provided with the auxiliary core 14 so as to be elastically limited. There is no fear of extending to a value or more, and the fracture portion C fixed by the medical linear member 10 has a contraction force f1a that tries to return to the pitch P1 before extension and an expansion force that tries to return to the outer diameter D1. The envelope pressure composed of f1b always acts from the outer periphery of the fractured part C toward the center side.

[Operation of Example 2]
In the fractured part C fixed by the medical linear member 10 of Example 2, the contraction force f1a that tries to return to the pitch P1 and the dimension S1 of the gap part before expansion, and the expansion force f1b that tries to return to the outer diameter D1. The capsule pressure consisting of always acts from the outer periphery of the fractured part C toward the center side.
In addition, since the medical linear member 10 is wound around the fractured part C, the cross-sectional shape is deformed from a substantially circular shape to a flat elliptical shape, so that the contact of the medical linear member 10 with the fractured part C becomes surface contact. The fixed state of the fractured part C is stabilized and a restoring force for returning to the substantially circular cross-sectional shape always acts toward the center side of the fractured part C.
Moreover, since the slipperiness of the outer surface of the medical linear member 10 improves by coat | covering the outer periphery of a helical body with the resin coating layer 15, the internal tissue and the medical linear member 10 by the body movement and pulsation after a surgery are improved. Therefore, adverse effects on the body tissue other than the treatment target site can be reduced.

Claims (4)

A basic body in which a plurality of wires are arranged is a spiral body spirally wound with a space inside and a gap in the axial direction, and the outer periphery of the spiral body is covered with a resin coating layer. A linear member for medical use. The linear member according to claim 1, further comprising an auxiliary core made of one or more wires formed in a bent shape in at least a part of the space. The medical linear member according to any one of claims 1 to 2, wherein all or a part of the wires of the basic body are made of metal. The medical linear member according to any one of claims 1 to 3, wherein metal plating is applied to at least a part of the basic body or the resin coating layer.

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