JP2008017954A - Bone cutting wire and wire guide tube used therein - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bone cutting wire with improved cutting capability, hardly scattering cutting dust. <P>SOLUTION: The bone cutting wire 10 comprises a core strand 11 with a plurality of twisted metal wires 21 and 22, and a plurality of side strands 12 and 13 twisted in the outer periphery of the core strand 11. Each of the side strands 12 and 13 is composed of a plurality of twisted metal wires 23 and 24. The thick side strand 12 and the thin side strand 13 are alternately disposed. The side strands 12 and 13 are twisted to the core strand 11 by the Lang's lay, and the braiding angle is at least 30 degrees. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an osteotomy wire, in particular, a medical osteotomy wire and a wire guide tube used for the osteotomy wire.

JP 2006-20824 A JP 2002-282263 A Registered Utility Model No. 3018201

  Paragraph [0003] of Patent Document 1 discloses “a stranded wire-shaped wire knife in which a plurality of wire wires are closely twisted” as a wire knife for cutting soft tissues such as skin and muscle.

  Paragraph [0014] of Patent Document 2 discloses a “string-like wire made of stainless steel filaments” as an osteotomy wire for osteogenic laminectomy. However, specific configurations such as the diameter and number of strands and the twisted shape are not clearly shown. In addition, a guide pipe that guides the osteotomy wire by caulking a spherical tip metal fitting to the tip of the twisted osteotomy wire is also disclosed.

  Paragraph [0009] of Patent Document 3 mentions “knitted wire” as a wire serving as a saw blade, and further mentions “single wire with a rough surface” and “twisted wire”. The meaning of “knitted wire” here is unknown, and no specific configuration is described for the stranded wire. On the other hand, a 7 × 7 type osteotomy wire having an outer diameter of 0.55 mm, in which seven strands of stainless steel having a diameter of 0.2 mm are twisted and seven strands obtained are twisted, has been put into practical use.

  A conventional osteotomy wire composed of a 7 × 7-type stranded wire has insufficient cutting ability, and it is difficult to cut hard bone along a complicated path, particularly in the operation of a cervical vertebra. Furthermore, it is desirable to prepare various cutting and cutting properties for the bone cutting wire according to the type and location of the bone, but the irregular shape is determined by the normal stranded wire, and the desired irregular shape is obtained. In particular, large irregularities cannot be formed in the longitudinal direction.

  The present invention provides an osteotomy wire with improved machinability and flexibility as compared with these conventional products, and in particular, it is easy to make the uneven shape in the longitudinal direction a desired shape, and it is possible to make the uneven shape particularly large. It is a technical problem to provide a bone cutting wire.

  Further, the conventional wire knife, osteotomy wire, or osteotomy wire with diamond powder fixed on the surface has a problem that the bone cutting powder or diamond powder is easily scattered in the body. In particular, in the case of diamond, there is a problem that it is caught by bones during cutting. It is a third technical object of the present invention to provide an osteotomy wire that is difficult to disperse powders such as bones and diamonds and is not easily caught by bones.

  Furthermore, since the conventional guide pipe is made of metal and is hard and difficult to bend, there is a possibility of damaging living tissues, particularly nerves, during insertion. A fourth technical object of the present invention is to provide a wire guide tube that can be inserted safely and easily.

  An osteotomy wire according to the present invention (Claim 1) includes a core strand obtained by twisting a plurality of metal strands and a plurality of side strands twisted around an outer periphery of the core strand. Among the side strands, at least one side strand is obtained by twisting a plurality of metal strands, and the side strand obtained by twisting the metal strands is Lang twist and the twist angle is 30 degrees or more. It is characterized by being.

  In such an osteotomy wire, it is preferable that at least one of the plurality of side strands has an outer diameter different from that of an adjacent side strand (Claim 2). Moreover, it is preferable that at least one of the side strands is a single wire, and the outer diameter thereof is smaller than the outer diameter of the adjacent side strand. Furthermore, it is preferable that at least one of the single wires has a polygonal cross section. Further, it is preferable that the surface roughness of at least a part of the side strand is 0.1 to 40 μm of Ra (Claim 5).

  The wire guide tube of the present invention (Claim 6) is a wire guide tube for guiding any of the above-described osteotomy wires, and has a distal end portion that is more flexible than a proximal portion, and an end portion of the proximal portion. It is characterized in that a guide part serving as an insertion port for the osteotomy wire is provided.

  In such a wire guide tube, it is preferable that the vicinity of the tip bends or curves in a substantially L shape or loop shape. In that case, it is preferable that the guide component is provided with a mark indicating the direction of bending or bending near the tip. Further, a wire guide tube in which a reinforcing layer made of a thin wire is provided at the proximal portion is more preferable.

  The osteotomy wire / tube set of the present invention (Claim 10) is characterized by comprising any one of the osteotomy wires and any one of the wire guide tubes for guiding the osteotomy wire.

  In the osteotomy wire of the present invention (Claim 1), the side strand obtained by twisting the metal strands is Lang twisted (a twist in which the winding direction of the side strand with respect to the core strand is the same as the twisting direction of the side strand. However, since the twist angle is 30 degrees or more, the metal strand of the side strand becomes a large angle with respect to the center line of the osteotomy wire. Therefore, a large cutting force is exerted on the bone, and the cutting efficiency is high.

  In such an osteotomy wire, when the outer diameter of at least one side strand of the plurality of side strands is different from the outer diameter of the adjacent side strand (Claim 2), a spiral protrusion or Since the concave groove is formed, the cutting efficiency is higher. That is, when the outer diameter of one side strand is larger than the outer diameter of the adjacent side strand, a spiral protrusion is formed. For this reason, when viewed in the longitudinal direction, the side strand protrudes by a level difference for each twisted pitch of the side strand. Therefore, when the osteotomy wire is reciprocated against the bone, the projecting portion strongly cuts the bone out of the portion hitting the bone, so that the cutting efficiency is high.

  On the other hand, when the diameter of one side strand is smaller than that of the adjacent side strand, the concave groove is formed in a spiral shape. Also in this case, a portion recessed in the length direction appears for every twist pitch, and the cutting efficiency is increased. Also, by selecting the difference in diameter between adjacent side strands, it is possible to arbitrarily set the step of the protrusion or dent, and by selecting the number of side strands with different diameters, the pitch of the protrusion or dent portion Can be set freely. Thereby, the osteotomy wire of the cutting characteristic according to the detailed demand of a practitioner can be manufactured.

  In the case where at least one of the side strands is a single wire and the outer diameter thereof is smaller than the outer diameter of the adjacent side strand (Claim 3), the strength of the entire osteotomy wire is determined by the single wire side strand. And rigidity becomes high. Therefore, durability is high and there are few accidents which break during a treatment. Moreover, since the outer diameter of the single strand is smaller than that of the strand side strand, it does not interfere with the cutting of the strand side strand, and the cutting efficiency does not decrease.

  When at least one of the single wires has a polygonal cross section (Claim 4), the twist is difficult to unwind despite the large twist angle. It is also possible to cut bone at the corners of a single wire. Furthermore, when the surface roughness of at least a part of the side strand is 0.1 to 40 μm of Ra (Claim 5), the bone can be efficiently cut.

  Since the wire guide tube of the present invention (Claim 6) has a flexible tip, it is easy to follow the bone, and even if it comes into contact with the nerve in the vicinity of the bone, the nerve is not damaged. Safety is improved. Moreover, since the hand portion is harder than the tip portion, the guide property is high, and the shape retaining property is excellent even when the osteotomy wire is inserted. Moreover, since the rigidity of a hand part is high, it is excellent also in operability. Further, since the guide part is provided at the hand portion, the osteotomy wire can be easily inserted.

  A wire guide tube that is bent or curved in a substantially L-shape or loop shape in the vicinity of the distal end portion can easily follow the osteotomy wire while avoiding nerves or the like with respect to the bone at a deep position in the body ( Claim 7). In addition, when the guide component is provided with a mark indicating the direction of bending or bending near the tip (Claim 8), the direction of bending or bending of the wire guide tube can be known from outside the living body. Therefore, it is easy to control the insertion direction of the osteotomy wire. Furthermore, the wire guide tube in which the reinforcing layer made of a thin line is provided at the proximal portion has a high guiding property at the proximal portion (claim 9).

  Since the osteotomy wire and tube set of the present invention (Claim 10) combines the aforementioned osteotomy wire and wire guide tube, both effects can be achieved.

  Next, an embodiment of the osteotomy wire of the present invention will be described with reference to the drawings. 1 is a cross-sectional view showing an embodiment of the osteotomy wire of the present invention, FIG. 2 is a side view of the main part of the osteotomy wire, and FIG. 3 is a cross-sectional view showing another embodiment of the osteotomy wire of the present invention. FIG. 4 is a side view of the main part of the osteotomy wire, FIGS. 5 and 6 are schematic side views showing how to use the osteotomy wire of the present invention, and FIG. 7 shows an embodiment of the wire guide tube of the present invention. 8a and 8b are cross-sectional views taken along lines AA and BB in FIG. 5, respectively, FIG. 9 is a side view showing another embodiment of the wire guide tube of the present invention, and FIG. 9 is a cross-sectional view taken along line XX, FIG. 11 is a process diagram showing a method of placing the osteotomy wire around the bone using the osteotomy wire of the present invention together with a wire guide tube, and FIG. 12 is a comparative osteotomy wire. FIG. 13 is a side view of the present invention, and FIG. Schematic side view of location, FIG. 14 is a graph showing the results of the cutting test.

  The osteotomy wire 10 shown in FIG. 1 includes one core strand 11 and six side strands 12 and 13 twisted around the outer periphery thereof. Each of the core strand 11 and the side strands 12 and 13 is a stranded wire obtained by twisting a plurality of metal strands. Furthermore, as the side strands 12 and 13, large-diameter side strands 12 having a large diameter and small-diameter side strands 13 having a small diameter are alternately arranged. However, only one or two side strands 12 may have a large diameter, and only one or two side strands 12 may have a small diameter. Thereby, the diameter of adjacent side strands 12 and 13 differs.

  In this embodiment, a strand in which six metal strands 22 are twisted around one thin metal strand 21 is used as the core strand 11. The side strands 12 and 13 are also made by twisting six metal strands 24 around one metal strand 23. That is, the osteotomy wire 10 is a so-called 7 × 7 stranded wire as a whole. The core strand 11 obtained by twisting the thin metal wires 21 and 22 in this way has high flexibility or flexibility. Further, the side slands 12, 13 obtained by twisting the thin metal wires 23, 24 are also highly flexible and flexible. Therefore, it is easy to cut the bone around the bone.

  The metal strands 21 and 22 constituting the core strand 11 and the metal strands 23 and 24 constituting the side strands 12 and 13 are high in strength and flexible, particularly hard steel wires and piano wires. Stainless steel wire can be used. The overall diameter of the core strand 11 is preferably about 0.1 to 1 mm, particularly preferably about 0.2 to 0.6 mm. And the diameter of the metal strands 21 and 22 which comprise the core strand 11 is about 0.05-0.1 mm, Especially about 0.06-0.08 mm is preferable. The twist angle (symbol θ in FIG. 2) of the side strands 12 and 13 is 30 ° or more with respect to the core strand 11, particularly preferably about 30 to 40 °, and is a Lang twist.

  On the other hand, the diameters of the side strands 12 and 13 are substantially the same as the diameter of the core strand 11, respectively, but the diameter of the large side strand 12 is about 0.01 to 0.1 mm from the diameter of the small side strand 13, Preferably it is about 0.01-0.05 mm large. As a result, unevenness having a step of 0.01 to 0.1 mm, preferably 0.01 to 0.05 mm, is formed on the osteotomy wire 10. Such a difference in diameter between the side strands 12 and 13 is obtained by using metal strands 23 and 24 constituting the side strands 12 and 13 having different diameters.

  In the osteotomy wire 10 of FIG. 2, the twist angle θ of the side strands 12 and 13 with respect to the core strand 11 (the angle of the side strand 13 with respect to the center line C of the metal strand 24) is 30 degrees or more. Therefore, the inclination angle of the step is strong and the cutting efficiency is high. In the case of a general stranded wire, the twist angle θ is about 15 to 25 ° that is the vicinity of the angle of repose so that the twist is difficult to unwind. However, the osteotomy wire 10 of FIG. 2 is 5-15 ° larger than the normal twist angle. The twist angle of the side strands 12 and 13 may be 30 ° or more, but is preferably 35 ° or more. Thereby, the cutting efficiency is further increased. The upper limit of the twist angle θ of the side strands 12 and 13 is 45 °, preferably 40 °. The twist pitch P is preferably about 2 to 6 mm.

  Further, in the osteotomy wire 10 of FIG. 2, Lang twisting is adopted in which the winding direction of the side strands 12 and 13 with respect to the core strand 11 is the same as the twisting direction of the side strands 12 and 13. For this reason, the metal wire 24 hits the bone to be cut at a large angle, the axial component of the force applied increases, and the lateral component decreases. Accordingly, the cutting efficiency is further increased.

  Further, in the osteotomy wire 10 of FIG. 2, the large-diameter side strands 12 and the small-diameter side strands 13 are adopted as described above, and they are alternately arranged and twisted around the outer periphery of the core strand 11. Therefore, as shown in FIG. 2, by arranging the strands 12 and 13 in a spiral shape, irregularities can be alternately formed in the longitudinal direction. For example, as viewed from the lower end of FIG. 2, the region T in which the large-diameter side strand 12 appears is a protruding portion, and the region H in which the small-diameter side strand 13 appears is a concave portion. And since the unevenness | corrugation of the level | step difference D is made in a longitudinal direction in this way, when the lower end side of the osteotomy wire 10 is applied to a bone and it reciprocates, an unevenness | corrugation will touch a bone | frame alternately and will be cut. And this uneven | corrugated level | step difference D is much larger than the unevenness | corrugation based on a metal strand being arranged, and the pitch of an unevenness | corrugation is also large.

  In the osteotomy wire 10 of FIG. 2, the large-diameter side strand 12 is detached from the lower end and is replaced with the small-diameter side strand 13, so that the stepped concave area continues until the next large-diameter side strand 12 comes to the lower end. . Therefore, cutting efficiency is high. Further, in this osteotomy wire 10, the entire surface of the side strands 12 and 13 is subjected to a treatment for roughening the surface such as sand blasting or shot peening, and the surface roughness is set to Ra of 0.1 to 40 μm. Thereby, the cutting efficiency is further improved. In addition, after twisting the side strands 12 and 13 to the core wire 11, you may perform the process which roughens the surface.

  3 and FIG. 4 and the small diameter side strand 13 of the osteotomy wire 10 of FIGS. 1 and 2 are replaced with a single side strand 27. That is, the large strand wire side strands 12 and the small diameter single wire side strands 27 are alternately arranged, and in this embodiment, three strands are employed. The material of the single side strand 27 may be the same as that of the metal strands 21, 22, 23, 24 described above. However, other materials can be used. The cutting efficiency of the single-wire side strand 27 is further improved by making the cross-section polygon, particularly a triangle. In this case, the side strand 27 having a polygonal cross section may be spirally wound while being twisted in the same direction as the twist direction or in the opposite direction, or may be spirally wound without being twisted.

  The osteotomy wire 26 configured in this manner has a lower half of flexibility and flexibility, strength and rigidity than the osteotomy wire 10 of FIGS. Therefore, it is highly durable even when used on hard bones. In the case of a hard bone, since the diameter is relatively large, the curvature radius in a curved state is also large. Therefore, low flexibility is not a big problem. As for the cutting performance, even in the case of the osteotomy wire 10 of FIGS. 1 and 2, since the large-diameter side strand 12 is mainly responsible, this osteotomy wire 26 can obtain substantially the same cutting efficiency. By using a single wire, the diameter can be further reduced, and in that case, the step D in the longitudinal direction can be further increased.

  It is the same as that of the osteotomy wire 10 of FIGS. 1-2 also about making the side strand 12 of a strand wire into Lang twist, and making a twist angle 30 degree | times or more, Preferably it is 35 degree | times or more. Play. Moreover, it is the same as that of the osteotomy wire 10 of FIGS. 1-2 also about the point to which the process of roughening the surface roughness of the strand side strand 12 and the single side strand 27 is preferable.

  The osteotomy wire 10 of FIG. 1 and the osteotomy wire 2 of FIG. 3 configured as described above are used to cut or cut bone, and the length is selected according to the purpose. Usually, it is about 600 to 800 mm. In the following description, the osteotomy wire 10 of FIG. 1 will be described, but the same applies to the osteotomy wire 26 of FIG.

  For example, as shown in FIG. 5, the osteotomy wire 10 is wound around the bone 30, changed in direction to be easily operated by the pulleys 31 and 32, and alternately pulled at both ends. As a result, the irregularities on the surface of the osteotomy wire 10 alternately hit the bone 30 and gradually bite into the bone 30 as if they were sawed. Thereby, the bone 30 can be provided with a predetermined depth of cut or cut. Further, since diamond particles are not used, there is no catching at the time of cutting, and diamond particles do not fly into the body.

  Next, an embodiment of a wire guide tube that guides the bone cutting wires 10 and 26 to the vicinity of the bone will be described with reference to FIGS. A wire guide tube 35 shown in FIG. 7 includes a flexible tip portion (soft tip) 36, a flexible hand portion (main body) 37, and a guide component 38 provided at an end portion of the hand portion 37. .

  As shown in FIG. 8a, the tip portion 36 is a flexible cylindrical member made of soft synthetic resin. The reason for making the tip portion flexible is to prevent the living body from being damaged when inserted into the living body. As the synthetic resin, thermoplastic resins such as polyamide, polyurethane, polyethylene, polypropylene, polyester, and fluorine resin, and elastomers thereof are used. In particular, polyamide elastomer is preferred because of its high flexibility and strength. A double or more multilayer structure may be used, and a material having low sliding resistance such as fluorine resin may be used on the inner surface side, and a material having high flexibility such as polyamide (PA) may be used on the outer surface side. . The length L1 of the tip portion 36 is usually 0.5 to 5 mm, and preferably about 1 mm.

  As shown in FIG. 8 b, the hand portion 37 includes an inner layer tube 39, a braided layer 40 provided around the inner tube 39, and a covering layer 41 that covers the braided layer 40. The covering layer 41 is filled in the gap between the braided layers 40. The inner tube 39 has low sliding resistance such as polytetrafluoroethylene (PTFE), perfluoroalkoxyalkane (PFA), perfluoro (ethylene, propylene) / tetrafluoroethylene / hexafluoropropylene copolymer (FEP), A fluorine-based resin having high wear resistance is preferable. This is because the braided layer of the osteotomy wire is in sliding contact with the inner surface of the inner layer tube 39. The hand portion 37 has higher rigidity than the tip portion, but has a certain degree of flexibility and elasticity. This is because the direction of travel may be changed around the bone when inserted into the living body.

  The braided layer 40 is a layer in which the metal strands 42 are braided. The material of the metal strand 42 may be the same as that of the metal strands 21 and 22 of the core strand 11, or the material may be changed. The diameter of the metal strand 42 is, for example, about 0.02 to 0.3 mm, and more preferably about 0.04 to 0.06 mm. When the thickness is less than 0.02 mm, the strength is weakened, and when it exceeds 0.3 mm, the flexibility is lowered and the braiding process is difficult. In addition, you may employ | adopt the resin strand which consists of a synthetic resin with high intensity | strength.

  The covering layer 41 protects the braided layer 40 from direct contact with living tissue, and a synthetic resin such as polyamide (PA), polyethylene (PE), or polyurethane (PUR) is employed. The length of the hand portion 37 is determined by the position and depth of the bone to be cut, but is usually about 100 to 300 mm, preferably about 200 mm.

  For such a wire guide tube 35, for example, a hand portion 37 formed in an elongated shape is cut to an appropriate length, and a tip end portion 36 is injection-molded at one end thereof, or at the same time or separately, a guide component 38 at the other end. Can be manufactured by injection molding. The three parts may be manufactured separately and joined together.

  In the wire guide tube 35 configured as described above, the distal end portion of the osteotomy wire is cut by inserting the osteotomy wire into the cavity 43 at the center or by inserting the osteotomy wire into the living body using only the wire guide tube 35. Try to come near the bone you want to try. Thereafter, the wire guide tube 35 is removed from the living body, the osteotomy wire is wound around the bone, and as shown in FIG. 5 or 6, the osteotomy wire is alternately pulled to cut the bone, or the bone is cut. Or put it in.

  The wire guide tube 44 shown in FIG. 9 has a shape bent in an L shape at a position of about 20 to 150 mm from the tip. The bent portion 45 is at the hand portion 37 and is somewhat rounded to facilitate passage of the osteotomy wire. It may be curved in a loop shape (see FIG. 11). Further, as shown in FIG. 10, the guide part 38 of the wire guide tube 44 is provided with a projection 46 in the bending direction. Thereby, when the wire guide tube 44 is inserted into the living body, the bending direction can be known from the outside. As long as it is a mark that indicates the bending direction, a mark may be provided instead of the protrusion 46 or a recess may be formed.

  Next, with reference to FIG. 11, a method of hanging the osteotomy wires 10, 20, 20a, 24 around the bone 30 inside the body will be described. First, a wire guide tube 47 bent or curved near the tip and a stylet (core metal) 48 to be inserted therein are prepared. When the stylet 48 is inserted into the wire guide tube 47, the curved portion 49 of the wire guide tube 47 is straightened (first step S1 in FIG. 11). In this state, the tip of the wire guide tube 47 is inserted to the side of the bone 30.

  Then, the wire guide tube 47 is inserted while gradually removing the stylet 48. Thereby, the bending portion 49 of the wire guide tube 47 advances along the periphery of the bone 30 while gradually returning to the original bending shape. Therefore, the wire guide tube 47 can be disposed so that the vicinity of the distal end is wound around the bone 30 in a semicircular shape (second step S2).

  Next, the stylet 48 is removed from the wire guide tube 47 while leaving the wire guide tube 47 in that state. Next, the aforementioned osteotomy wire 10 or the like is inserted into the wire guide tube 47 (third step S3). The osteotomy wire 10 advances around the bone 30 while being guided by the curved wire guide tube 47. The distal end of the osteotomy wire 10 may protrude from the distal end of the wire guide tube 47.

  Next, when the bone cutting wire 10 is left in that state and only the wire guide tube 47 is pulled out, the bone cutting wire 10 is wound around the bone 30 (fourth step S4). Thereafter, the both ends of the osteotomy wire 10 can be alternately pulled by the method shown in FIG. 5 to cut or cut the bone 30.

  As described above, the wire guide tube 47 whose tip vicinity is curved in a loop shape and the straight stylet 48 are combined, and the stylet 48 is inserted into or removed from the wire guide tube 47, whereby the wire The shape of the distal end portion of the guide tube 47 can be changed from a linear shape to a loop shape or from a loop shape to a linear shape by remote control. Therefore, the wire guide tube 47 can be inserted along the circumference of the bone, and the nerve around the bone is not damaged.

  Next, the effects of the osteotomy wire of the present invention will be described with reference to examples and comparative examples. [Example 1] Seven strands made of SUS304 having a circular cross section each having an outer diameter of 0.06 to 0.08 mm were twisted to form a core strand and a side strand having an outer diameter of 0.19 mm. Six side strands were twisted around the core strand by Lang twist and twisted at a twist angle of 38 degrees and a pitch of 4.0 mm to produce the osteotomy wire of Example 1 having the form shown in FIGS. The outer diameter of the osteotomy wire was 0.57 mm.

  [Example 2] Three side strands having an outer diameter of 0.19 mm in Example 1 and three side strands made of SUS304 single wire having an outer diameter of 0.15 mm are alternately arranged to make a total of six side strands. Otherwise, the osteotomy wire of Example 2 was obtained in the same manner as Example 1.

  [Comparative Example 1] Seven strands of SUS304 having a circular cross section each having an outer diameter of 0.07 mm were twisted to form a core strand and a side strand. Six side strands were twisted around the core strands at a twist angle of 25 degrees and a pitch of 4.0 mm to obtain the osteotomy wire of Comparative Example 1 shown in FIG. The outer diameter was 0.64 mm.

[Cutting degree measurement]
As shown in FIG. 13, the osteotomy wires of Examples 1 and 2 and Comparative Example 1 having a length of 200 mm of the effective cutting portion in which an 80 g weight 52 is attached to one end of a commercially available gypsum board 51 having a thickness of 9.5 mm. The weight 61 was reciprocated up and down by pulling the other end in the direction of arrow J and then loosening the pulling force, and the cutting depth Dp of the gypsum board 51 was measured when this was repeated 10 times. In addition, it cut only when it pulled in the arrow J direction, and it did not cut at the time of return.

[Measurement Results] Table 1 and FIG. 14 show the measurement results of the degree of cutting.

  From the above experiment, the osteotomy wires of Examples 1 and 2 have a cutting depth of about 1.3 times that of Comparative Example 1, and the degree of cutting is high.

It is sectional drawing which shows one Embodiment of the osteotomy wire of this invention. It is a principal part side view of the osteotomy wire of FIG. It is sectional drawing which shows other embodiment of the osteotomy wire of this invention. It is a principal part side view of the osteotomy wire. It is a schematic side view which shows the usage method of the osteotomy wire of this invention. It is a schematic side view which shows the usage method of the osteotomy wire of this invention. It is a side view which shows one Embodiment of the wire guide tube used with the osteotomy wire of this invention. 8a and 8b are cross-sectional views taken along lines AA and BB in FIG. 7, respectively. It is a side view which shows other embodiment of the wire guide tube of this invention. FIG. 10 is a sectional view taken along line XX in FIG. 9. FIG. 3 is a process diagram illustrating a method for placing an osteotomy wire around a bone using the osteotomy wire of the present invention with a wire guide tube. It is a side view of the osteotomy wire of the comparative example 1. It is a schematic side view of the apparatus which measures the machinability of the osteotomy wire of this invention. It is a graph which shows the result of a cutting test.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Bone cutting wire 11 Core strand 12 Large diameter side strand 13 Small diameter side strand 14 Tip member 21, 22
23, 24 Metal strand (side strand)
16 Metal strand (side wire)
θ twist angle P pitch T projecting part H recessed part D step C center line 17 metal strand 26 osteotomy wire 27 single strand side strand 30 bone 31, 32 pulley 33 tibia 34 cervical spine 35 wire guide tube 36 distal end (Soft chip)
37 Hand part 38 Guide part 39 Inner layer tube 40 Braided layer 41 Cover layer 42 Metal wire 43 Cavity 44 Wire guide tube 45 Bending part 46 Protrusion 47 Wire guide tube 48 Stylet 49 Bending part 51 Gypsum board 52 Weight

Claims (10)

A core strand formed by twisting a plurality of metal strands;
A plurality of side strands twisted around the outer periphery of the core strand,
Among the plurality of side strands, at least one side strand is obtained by twisting a plurality of metal strands,
A bone cutting wire in which the side strand obtained by twisting the metal strands is a Lang twist and the twist angle is 30 degrees or more.   The osteotomy wire according to claim 1, wherein an outer diameter of at least one of the plurality of side strands is different from an outer diameter of an adjacent side strand.   The osteotomy wire according to claim 1, wherein at least one of the side strands is a single wire, and an outer diameter thereof is smaller than an outer diameter of an adjacent side strand.   The osteotomy wire according to claim 3, wherein at least one of the single wires has a polygonal cross section.   The osteotomy wire according to claim 1, wherein the surface roughness of at least a part of the side strand is 0.1 to 40 µm of Ra. A wire guide tube for guiding the osteotomy wire according to any one of claims 1 to 5,
A wire guide tube having a distal end portion that is more flexible than the proximal portion and a guide component that serves as an insertion port for the osteotomy wire is provided at the end portion of the proximal portion.   The wire guide tube according to claim 6, wherein the vicinity of the tip is bent or curved in a substantially L shape or loop shape.   The wire guide tube according to claim 7, wherein the guide component is provided with a mark indicating a direction of bending or bending near the tip.   The wire guide tube according to claim 6, wherein a reinforcing layer made of a thin wire is provided at the proximal portion. An osteotomy wire / tube set comprising the osteotomy wire according to any one of claims 1 to 5 and the wire guide tube according to any one of claims 6 to 9 for guiding the osteotomy wire.

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