WO2016047380A1

WO2016047380A1 - Bone fastener and manufacturing method for same

Info

Publication number: WO2016047380A1
Application number: PCT/JP2015/074594
Authority: WO
Inventors: 圓井　良
Original assignee: 圓井繊維機械株式会社
Priority date: 2014-09-24
Filing date: 2015-08-31
Publication date: 2016-03-31
Also published as: JP5807885B1; JP2016063886A

Abstract

Provided is a bone fastener that can suitably fasten a bone piece that has been broken or cut. A bone fastener (1) is used for fastening a first and a second bone piece (21, 22) to be fastened and comprises a first cylindrical portion (11) into which the first bone piece 21 is inserted and a second cylindrical portion (12) into which the second bone piece (22) is inserted and that is coupled with the first cylindrical portion (11). The first and the second cylindrical portions (11, 12) are formed by a fiber reinforced resin that includes a matrix resin that is a first biodegradable resin and a fiber reinforced with a second biodegradable resin that has a melting point higher than the first biodegradable resin.

Description

Bone fixing device and manufacturing method thereof

The present invention relates to a bone anchor or the like made of a biodegradable resin fiber reinforced resin.

Conventionally, it has been practiced to insert a PLA connecting pin into a rib separation part and fix the rib (for example, see Non-Patent Document 1). Biodegradable resins such as PLA are decomposed and absorbed in the body within several months and do not remain in the body. Therefore, as in the case where the ribs are fixed using a non-biodegradable ceramics or other joint pin (implant), the joint pin does not have an adverse effect on the living body. There is an advantage that there is no need to do.

However, when the conventional joining pin is used, there is a problem that the bone to be fixed may come off the joining pin. When the joining pin is detached from the bone to be fixed as such, the bone cannot be appropriately fixed. In addition, when the bone to be fixed is thin, there is a problem that it is difficult to insert the joining pin.

This invention was made in order to solve the said subject, and it aims at providing the bone fixing tool which can fix the bone | frame of fixation object without using a joining pin.

In order to achieve the above object, a bone fixation device according to the present invention is a bone fixation device used for fixing first and second bone fragments to be fixed, in which the first bone fragment is inserted. 1 tubular portion, and a second tubular portion connected to the first tubular portion, into which a second bone fragment is inserted, the first and second tubular portions, It is comprised by the fiber reinforced resin containing the matrix resin which is 1st biodegradable resin, and the reinforced fiber of 2nd biodegradable resin which has melting | fusing point higher than 1st biodegradable resin.
With such a configuration, the joint portion of the bone fragment is surrounded by the bone fixing tool, so that the possibility that the bone fragment to be fixed comes off from the bone fixing tool can be reduced. As a result, the bone piece to be fixed can be appropriately fixed until the bone is fused. Moreover, since it fixes so that a bone piece may be surrounded, it can be used also for the thin bone piece which is hard to join with a joining pin. Moreover, since it is composed of fiber reinforced resin, it is possible to provide a bone fixture that has high strength and is difficult to break.

Moreover, in the bone fixing tool by this invention, the side surface of the 1st and 2nd cylindrical part may have liquid permeability.
With such a configuration, blood, lymph, and the like necessary for bone unity can be easily supplied to the joint part of the bone piece, and bone fusion can be promoted.

In the bone anchor according to the present invention, a gap corresponding to the third bone fragment exists between the first and second bone fragments, and the third cylindrical portion corresponding to the third bone fragment is provided. Furthermore, the 1st and 2nd cylindrical part is connected through the 3rd cylindrical part, and the 3rd cylindrical part may also be comprised with fiber reinforced resin.
With such a configuration, even when the third bone fragment is present between the first and second bone fragments, the first and second bone fragments can be fixed in consideration thereof. .

Moreover, in the bone fixing device by this invention, the liquid permeability may be lower than the side surface of the 1st and 2nd cylindrical part in the side surface of a 3rd cylindrical part.
With such a configuration, for example, by inserting gelatin or a bone regeneration promoter into the inside of the third cylindrical portion and fixing the first and second bone fragments, It is possible to promote the regeneration of the bone at the location. In such a case, the liquid permeability of the side surface of the third cylindrical portion is low, so that the gelatin or the like can hardly flow out of the bone anchor.

Moreover, in the bone fixing tool by this invention, the 1st and 2nd cylindrical part may be shape | molded by the shape fitted to a 1st and 2nd bone piece, respectively.
With such a configuration, the wearability between the cylindrical portion and the bone fragment is improved, and more appropriate fixation can be realized.

In the bone anchor according to the present invention, the first biodegradable resin does not exist in a part of the first and second cylindrical portions in the length direction, and the fibers of the second biodegradable resin are not present. Each of the annular portions may be provided.
With such a configuration, it is possible to provide an annular portion of only fibers without the matrix resin in a part of the first and second cylindrical portions. Therefore, when the first and second bone fragments are fixed by the bone fixing tool, in the annular portion, for example, each tubular portion can be fixed to the bone fragments using a biodegradable thread or the like, It is possible to prevent the bone anchor from being displaced.

Further, in the bone anchor according to the present invention, the fiber reinforced resin includes fibers having the first and second biodegradable resins, the first biodegradable resin is melted, and the second biodegradable resin is melted. You may comprise by heating at the temperature which does not.
By using the fiber which has 1st and 2nd biodegradable resin by such a structure, the bone fixing tool of the fiber reinforced resin comprised by both can be easily manufactured now.

A method for manufacturing a bone fixing device according to the present invention is a method for manufacturing a bone fixing device used for fixing the first and second bone fragments to be fixed, the first biodegradable resin, A first cylindrical part into which the first bone fragment is inserted, and a first cylindrical part, using fibers of a second biodegradable resin having a higher melting point than the first biodegradable resin; The first biodegradable resin is melted in the molding step of molding a molded body having the same shape as the second cylindrical portion into which the second bone fragment is inserted, and the second body is melted. A heating step of heating at a temperature at which the biodegradable resin does not melt, and a solidifying step of lowering the temperature of the first biodegradable resin after the heating step to solidify, the first biodegradable resin First and second cylindrical shapes constituted by a fiber reinforced resin including a matrix resin and a reinforced fiber of a second biodegradable resin A method for producing a bone fastener having a.
With such a configuration, by easily heating a molded body constituted by the first biodegradable resin and the second biodegradable resin fiber, a fiber-reinforced resin bone anchor can be easily manufactured. Will be able to.

The method for manufacturing a bone fastener according to the present invention further includes a step of manufacturing a mold having the same shape as the first and second bone fragments, and the first and second steps are performed using the mold in the molding step. You may shape | mold the molded object which has a shape fitted with a bone piece.
With such a configuration, the mountability between the manufactured cylindrical portion and the bone fragment is improved, and more appropriate fixation of the bone fragment can be realized using the manufactured bone fixing tool.

Moreover, in the manufacturing method of the bone fixing device by this invention, you may shape | mold a molded object using the fiber which has 1st and 2nd biodegradable resin at a formation process.
With such a configuration, for example, a molded body can be formed from a knitted fabric, a woven fabric, a braid, or the like using a core-sheath composite fiber or a mixed fiber, and the molded body can be easily molded.

According to the bone fixing device or the like according to the present invention, when a bone fragment to be fixed is fixed by the bone fixing device, the possibility that the bone fragment is detached from the bone fixing device can be reduced. Can be fixed properly.

The figure which shows the bone fixing device by embodiment of this invention The figure which shows the state by which the bone fragment was inserted in the bone fixing tool by the embodiment The figure which shows the bone fixing tool by the embodiment The figure which shows the state by which the bone fragment was inserted in the bone fixing tool by the embodiment The flowchart which shows the manufacturing method of the bone fixing device by the embodiment The flowchart which shows the manufacturing method of the bone fixing device by the embodiment The figure which shows the bone fixing tool by the embodiment The figure which shows the state by which the bone fragment was inserted in the bone fixing tool by the embodiment The figure which shows the state by which the bone fragment was inserted in the bone fixing tool by the embodiment The figure which shows the shaping | molding die of the same shape as the bone piece in the embodiment The figure which shows the molded object with which the shaping | molding die in the same embodiment was mounted | worn The figure which shows the bone fixing tool shape | molded in the same shape as the bone fragment in the embodiment The figure which shows the bone fixing tool by the embodiment The figure which shows the state by which the bone fragment was inserted in the bone fixing tool by the embodiment

Hereinafter, the bone fixing device according to the present invention and the manufacturing method thereof will be described using embodiments. In the following embodiments, components and steps denoted by the same reference numerals are the same or equivalent, and repetitive description may be omitted. The bone anchor according to the embodiment of the present invention has a cylindrical portion made of a biodegradable fiber reinforced resin.

FIG. 1A is a diagram illustrating a bone fixing device 1 according to the present embodiment, and FIG. 1B is a diagram illustrating a state in which first and

second bone fragments

21 and 22 to be fixed are inserted into the bone fixing device 1. It is. Note that the bone piece to be fixed may be, for example, a rib bone or a bone of another part such as a clavicle or a limb bone. Further, the bone may be, for example, a human bone or a bone of a non-human animal.

The bone fastener 1 according to the present embodiment is used for fixing the first and

second bone fragments

21 and 22 to be fixed, and includes a first cylindrical portion 11 and a second cylindrical shape. Part 12. Note that the first and

second bone fragments

21 and 22 are originally connected bones that have lost continuity due to a fracture or cutting for the purpose of treatment or the like.

The first cylindrical portion 11 and the second cylindrical portion 12 are connected. The connection may be a direct connection as shown in FIG. 1A, or an indirect connection via another cylindrical portion as will be described later. In the former case, as shown in FIG. 1A, one cylindrical portion may be configured by the first and second

cylindrical portions

11 and 12. In addition, when the 1st and 2nd

cylindrical parts

11 and 12 are comprised as one cylindrical part, strictly, the boundary of the 1st and 2nd

cylindrical parts

11 and 12 is determined. Since this is difficult, for convenience, the opening 11a side will be referred to as the first cylindrical portion 11 and the opening 12a side will be referred to as the second cylindrical portion 12. Accordingly, the boundary line (the chain line) in FIG. 1A and the like is for convenience. In such a case, the first and second

cylindrical portions

11 and 12 are integrally formed. Moreover, the magnitude | size of the bone fixing tool 1 is not ask | required. It is preferable that the thickness (the size of the cross section orthogonal to the length direction) of the bone fixture 1 is approximately the same as the size of the cross section of the bone fragment to be fixed. Moreover, it is suitable that the cross-sectional shape of the 1st and 2nd

cylindrical parts

11 and 12 is the same as that of the cross-sectional shape of the bone piece of fixation object. The shape may be, for example, a circular shape, an elliptical shape, or a rounded rectangular shape. The length in the longitudinal direction may be, for example, 3 to 12 cm or 5 to 8 cm. Other lengths may be used within a range in which the bone fragment to be fixed can be appropriately fixed. It may be.

In the first cylindrical portion 11, the first bone piece 21 is inserted from the opening 11a on the opposite side to the second cylindrical portion 12. The second tubular portion 12 is configured such that the second bone piece 22 is inserted from the opening 12 a on the opposite side to the first tubular portion 11. Moreover, the inside of the 1st and 2nd

cylindrical parts

11 and 12 is connecting. Therefore, the end surfaces of the first and second bone fragments 21 and 22 inserted from both the

openings

11 a and 12 a can be contacted in the bone fixing device 1. Therefore, by fixing the first and second bone fragments 21 and 22 with the bone fixing tool 1, the fusion of the end surfaces of the first and second bone fragments 21 and 22 can be promoted.

The 1st and 2nd

cylindrical parts

11 and 12 are comprised by fiber reinforced resin (FRP) containing the matrix resin which is 1st biodegradable resin, and the reinforced fiber of 2nd biodegradable resin. . The second biodegradable resin has a higher melting point than the first biodegradable resin. Note that the first and second biodegradable resins may be the same resin or different resins. The biodegradable resin is not particularly limited. For example, polylactic acid (PLA), polyhydroxybutyrate, polyglycolic acid, cellulose acetate, glycolic acid / lactic acid copolymer (PGLA), polydioxanone (PDO), L-lactic acid / It may be ε-caprolactone copolymer (LCL), poly-L-lactic acid (PLLA) or the like. The biodegradable resin is usually a thermoplastic resin. Therefore, as will be described later, the first biodegradable resin melts the molded body formed using the first biodegradable resin and the fibers of the second biodegradable resin, and the second biodegradable resin is melted. By heating to a temperature at which the degradable resin does not melt, the bone anchor 1 composed of a biodegradable fiber-reinforced resin can be manufactured. In that case, the first biodegradable resin becomes the matrix resin, and the fibers of the second biodegradable resin become the reinforcing fibers. In addition, since it is necessary to fix the bone fragment until the bone fragment to be fixed is united, the bone fixing unit 1 uses a biodegradable resin that can exist in the living body for the period until the unit. 1 is preferable.

In addition, the side surfaces of the first and second

cylindrical portions

11 and 12 may have liquid permeability. In that case, the liquid outside the first and second

cylindrical portions

11 and 12 easily penetrates into the inside. As a result, for example, blood, lymph, or the like is easily supplied to the joint portion between the first and second bone fragments 21 and 22, and bone fusion at that portion is promoted. In addition, since the some hole exists in the side surface of the 1st and 2nd

cylindrical parts

11 and 12, those side surfaces may have liquid permeability. The plurality of holes are preferably fine within a range in which blood or the like circulates in order not to reduce the strength of the bone anchor 1. The plurality of holes may be present on the entire side surfaces of the first and second

cylindrical portions

11 and 12 or may be present on a part thereof. In the latter case, for example, the plurality of holes may exist at side portions corresponding to the joint portions of the first and second bone fragments 21 and 22.

Next, the manufacturing method of the bone anchor 1 is demonstrated using the flowchart of FIG. 2A.
(Step S101) Using the first biodegradable resin and the fibers of the second biodegradable resin, a molded body having the same shape as the first and second

cylindrical portions

11 and 12 is formed. Hereinafter, several molding methods of the molded body will be described.

(1) Method of forming with knitted fabric, woven fabric, or braid In this case, a molded body is molded with the knitted fabric, woven fabric, or braid using the fibers having the first and second biodegradable resins. The fibers having the first and second biodegradable resins may be, for example, core-sheath composite fibers having the second biodegradable resin as a core and the first biodegradable resin as a sheath, A composite fiber having a structure in which the first and second biodegradable resins are bonded to each other may be used, and a mixed fiber (one yarn obtained by mixing the fibers of the first and second biodegradable resins) Combing yarn) or other fibers having first and second biodegradable resins. For example, when the biodegradable resin is PLA, a core-sheath composite fiber having a sheath having a melting point of 170 ° C. and a core having a melting point of 230 ° C. may be used.

A cylindrical shaped body that is a knitted fabric may be formed by knitting fibers having the first and second biodegradable resins. The knitted fabric may be, for example, a cylindrical shape knitted by warp knitting or a cylindrical shape knitted by weft knitting. Alternatively, a tubular knitted fabric may be formed by connecting two opposing sides of a rectangular knitted fabric by sewing or bonding.

Alternatively, a cylindrical shaped body that is a woven fabric may be formed by weaving fibers having the first and second biodegradable resins. The fabric may be, for example, a cylindrical fabric. Alternatively, a tubular woven fabric may be formed by connecting two opposing sides of a rectangular woven fabric by sewing or bonding.

In addition, when forming a cylindrical shaped body by sewing a knitted fabric or a woven fabric, the thread used for the sewing may be, for example, a fiber having first and second biodegradable resins, It may be a fiber of the first or second biodegradable resin, or may be a fiber of other biodegradable resin. Moreover, when bonding a knitted fabric etc., it is suitable to bond using a biodegradable resin.
Moreover, you may shape | mold the cylindrical-shaped molded object which is a braid by assembling the fiber which has 1st and 2nd biodegradable resin.

(2) Method of forming by filament winding In this case, a cylindrical shaped body is formed by winding fibers having the first and second biodegradable resins around a forming die (mandrel). At that time, the mold may be rotated, or the fiber winding head side may be rotated. Moreover, you may wind the fiber which has 1st and 2nd biodegradable resin around the shaping | molding die of the same shape as the 1st and

2nd bone pieces

21 and 22 mentioned later.

(3) Method of molding by sheet winding In this case, the first biodegradable resin sheet and the second biodegradable resin fiber are wound around a mold (mandrel) to form a cylindrical shape. Shape the body. At that time, the mold may be rotated, or the winding head side of a sheet or the like may be rotated. The first biodegradable resin sheet wound around the mold may be, for example, a first biodegradable resin woven fabric, film, or non-woven fabric. Further, the second biodegradable resin fiber wound around the mold may be, for example, a fiber itself (filament winding) or a sheet of knitted fabric, woven fabric, nonwoven fabric, or the like. Moreover, it does not ask | require how many layers each the sheet | seat of 1st biodegradable resin and the fiber of 2nd biodegradable resin are made. For example, both of them may be one layer each, and the second biodegradable resin fiber may be sandwiched by the first biodegradable resin sheet (the former is two layers, the latter is one layer), Both may be multilayer.

(4) Method to shape | mold with a nonwoven fabric In this case, a molded object is shape | molded with a nonwoven fabric using the fiber which has 1st and 2nd biodegradable resin. That is, a non-woven fabric is used instead of the knitted fabric (1). In addition, the fiber which has 1st and 2nd biodegradable resin is the same as the case of said (1). Usually, since a nonwoven fabric is plane shape, you may shape | mold a cylindrical nonwoven fabric by connecting two opposing sides of a rectangular nonwoven fabric by sewing or adhesion | attachment.

(Step S102) The molded body molded in the molding step of Step S101 is heated at a temperature at which the first biodegradable resin is melted and the second biodegradable resin is not melted. The heating may be performed by, for example, an electric furnace or an oven, may be performed by an industrial dryer, or may be performed by other heating means. The temperature at which the first biodegradable resin melts and the second biodegradable resin does not melt is usually higher than the melting point of the first biodegradable resin, The temperature is lower than the melting point. For example, when heating the molded body formed of the above-described PLA core-sheath composite fiber having a sheath having a melting point of 170 ° C. and a core having a melting point of 230 ° C., it may be heated to 180 ° C., for example. . By this heating process, the first biodegradable resin contained in the molded body molded in the molding process is melted. The purpose of melting the first biodegradable resin is to constitute a fiber reinforced resin having the first biodegradable resin as a matrix resin and the second biodegradable resin as a reinforcing fiber. It is preferable to perform heating under conditions (for example, time, heating method, etc.) within a range in which the object can be achieved.

(Step S103) After the heating step of Step S102, the temperature of the first biodegradable resin is lowered and solidified. Reducing the temperature may be reducing the temperature to about room temperature. The temperature reduction may be performed, for example, by natural cooling or by forced cooling. In the former case, for example, the temperature of the heating target may be decreased by terminating the heating. By this solidification step, the first and second biodegradable resins constituting the molded body are cooled, and the matrix resin that is the first biodegradable resin and the reinforcement of the second biodegradable resin. A cylindrical bone fixture 1 made of a fiber reinforced resin containing fibers is completed.

Here, a method for making the side surfaces of the first and second

cylindrical portions

11 and 12 have liquid permeability will be briefly described. For example, in the case of the above (1) and (2), even if the first biodegradable resin is melted and solidified by using a coarse knitted fabric, woven fabric, braid, or winding molded body, You may make it not clog. Even in the case of (3) above, even after the first biodegradable resin is melted and solidified by making the fibers of the second biodegradable resin into a coarse knitted fabric, woven fabric, braid, or winding. , You may try not to clog your eyes. In this way, the side surface of the bone fastener 1 has liquid permeability due to the holes (holes between the fibers) present at the positions corresponding to the eyes of the fibers of the second biodegradable resin. Also good. Further, after the cylindrical shape of the fiber reinforced resin is configured as described above, a plurality of holes may be provided in the entire side surface or a necessary portion by, for example, a drill or a laser beam.

Next, how to use the bone anchor 1 will be briefly described. As shown in FIG. 1B, the first bone fragment 21 to be fixed is inserted from one opening 11a of the bone fixture 1, and the second bone fragment 22 to be fixed is inserted from the other opening 12a. Then, the end surfaces of the first and second bone fragments 21 and 22 are brought into contact with or close to each other in the bone fixing device 1. In this way, the fractured or cut first and second bone fragments 21 and 22 are fixed by the bone fixing device 1, and the bone fusion between them is promoted.

In the above description, the case where the bone fixing tool 1 fixes both of the first and second bone fragments 21 and 22 in contact with each other or close to each other has been described, but this need not be the case. For example, a gap corresponding to the third bone fragment may exist between the first and second bone fragments 21 and 22. The third bone fragment may be a single bone fragment or a plurality of bone fragments. In such a case, as shown in FIG. 3A, the bone anchor 1 may include a third cylindrical portion 13 corresponding to the third bone fragment. The third cylindrical portion 13 is the same as the first and second

cylindrical portions

11 and 12, and is composed of the above-described biodegradable fiber reinforced resin. The third cylindrical portion 13 is provided between the first and second

cylindrical portions

11 and 12 so as to communicate with them. Therefore, in this case, the first and second

cylindrical portions

11 and 12 are connected via the third cylindrical portion 13. Also in this case, as shown in FIG. 3A, the first to third cylindrical portions 11 to 13 may constitute one cylindrical portion. In addition, when manufacturing the bone fixing tool 1 provided with the 3rd cylindrical part 13, you may manufacture the bone fixing tool 1 long only by the length according to the 3rd cylindrical part 13. FIG.

When the first and second bone fragments 21 and 22 are fixed by the bone fixing device 1 having the third cylindrical portion 13, as shown in FIG. 3B, the third cylindrical portion 13 is used. Gelatin, a bone regeneration promoting agent, or the like may be inserted into the inner region 31 or the third bone piece 23 is inserted into the third cylindrical portion 13 as shown in FIG. 3C. May be. As shown in FIG. 3B, when a bone regeneration promoter or the like is inserted into the inner region 31 of the third cylindrical portion 13, the side surfaces of the first and second

cylindrical portions

11 and 12 pass through. Even if it has liquidity, it is preferable that the side surface of the third cylindrical portion 13 has lower liquid permeability than the side surfaces of the first and second

cylindrical portions

11 and 12. . This is to prevent the bone regeneration promoting agent and the like inserted into the internal region 31 from leaking outside through the side surface of the third cylindrical portion 13. Note that the liquid permeability of the side surface of the third cylindrical portion 13 is low, for example, compared to the side surfaces of the first and second

cylindrical portions

11, 12, the side surface of the third cylindrical portion 13. The number of holes may be small, the density of the holes may be low, the size of the holes may be small, or the side surface of the third cylindrical portion 13 may not have liquid permeability. Good. Thus, when using the bone fixing tool 1 from which the liquid permeability of the side surface of the 3rd cylindrical part 13 differs, the 1st and 2nd bone fragments 21 and 22 are the 1st and 2nd cylindrical shapes, respectively. It is preferable that both

bone pieces

21 and 22 are fixed so as to be located at the

portions

11 and 12. Further, when the third bone piece 23 is not inserted into the third tubular portion 13, the first and

second bone pieces

21 and 22 are prevented from entering the position of the third tubular portion 13. Therefore, for example, the size of the cross section of the third cylindrical portion 13 is made smaller than the size of the cross sections of the first and second

cylindrical portions

11 and 12, and the first and second bone fragments 21 and 22 are formed. It is good also as a shape which does not enter into the 3rd cylindrical part 13. FIG. In that case, the bone anchor 1 has a constricted shape at the position of the third cylindrical portion 13. However, it is preferable that a space in which the bone corresponding to the third bone fragment 23 can be regenerated exists in the third cylindrical portion 13.

Here, a method for changing only the liquid permeability of the side surface of the third cylindrical portion 13 will be briefly described. First, the case where the side surface of the bone fixing device 1 is given liquid permeability by the gap between fibers will be described. When the molded body is formed by the method (1), for example, the first and second

cylindrical portions

11 and 12 are formed on the eyes of the knitted fabric and the woven fabric in the region corresponding to the third cylindrical portion 13. The fibers used in the region corresponding to the third cylindrical portion 13 may be thicker than the first and second

cylindrical portions

11 and 12. Further, when the molded body is formed by the method (2), for example, the density of the filament winding in the region corresponding to the third cylindrical portion 13 is set to the first and second

cylindrical portions

11 and 12. The fiber to be wound in the region corresponding to the third cylindrical portion 13 may be thicker than the first and second

cylindrical portions

11 and 12. Moreover, when shape | molding a molded object by the method of said (3), the winding number of the sheet | seat of the 1st biodegradable resin in the area | region corresponding to the 3rd cylindrical part 13 is made into 1st and 2nd. The first and second cylindrical portions 11 may be formed of a first biodegradable resin sheet that is wound in an area corresponding to the third cylindrical portion 13. , 12 may be used. In addition, when a plurality of holes are physically provided by a drill or a laser beam so that the side surface of the bone fastener 1 has liquid permeability, for example, the side surface of the third tubular portion 13 It is not necessary to provide holes, or holes are formed so that the density is low or the size is small so that the number is smaller than the number of side surfaces of the first and second

cylindrical portions

11 and 12. It may be provided.

Further, the bone fixing tool 1 may have a shape that exactly fits the bone fragment to be fixed. That is, the 1st and 2nd

cylindrical parts

11 and 12 may be shape | molded by the shape fitted with the 1st and

2nd bone pieces

21 and 22, respectively. Therefore, for example, when the molded body is molded, the molded body may be molded so as to have a shape of a bone piece to be fixed. A method for manufacturing such a bone anchor 1 will be described with reference to the flowchart of FIG. 2B. In the flowchart of FIG. 2B, processes other than step S201 are the same processes as in the flowchart of FIG. 2A.

(Step S201) First, the shape information of the first and second bone fragments 21 and 22 to be fixed is acquired by using CT or the like. Then, using the shape information, the

molds

41 and 42 having the same shape as the first and second bone fragments 21 and 22 are manufactured by a 3D printer or the like as shown in FIG. 4A.

The subsequent molding process, heating process, and solidification process (steps S101 to S103) are the same as those in the flowchart of FIG. 2A, but in the molding process (step S101), the first and second samples are formed using a mold. A molded body having a shape that can be fitted to the

bone pieces

21 and 22 is formed. Specifically, as shown in FIG. 4B, the first and second bone pieces 21 and 22 (molding dies 41 and 42) are formed by molding a molded body 43 attached to the molding dies 41 and 42. You may shape | mold the molded object which has a shape which can be fitted. In that case, it is suitable that the shaping | molding die 41 and 42 is combined so that it may become the same shape as the 1st and

2nd bone pieces

21 and 22 after fixation. Further, it is preferable that the molded body 43 attached to the

molds

41 and 42 is in close contact with the

molds

41 and 42. Therefore, for example, the molded body 43 may be configured by the knitted fabric of (1) above. This is because the knitted fabric easily fits into various shapes. Further, when the molded body is formed by the filament winding described in (2) above, the fibers may be wound around the

molds

41 and 42. Further, when a molded body is formed by the sheet winding of (3) above, a sheet or the like may be wound around the forming dies 41 and 42.

In the heating step (step S102), the molded body 43 (FIG. 4B) attached to the molding dies 41, 42 may be heated, or the molded body 43 removed from the molding dies 41, 42 (FIG. 4C). ) May be heated. When the molded body 43 is a knitted fabric, it is preferable to heat the molded body 43 mounted on the molding dies 41 and 42. On the other hand, when the molded body 43 is formed by filament winding or sheet winding, and the shape of the molded body 43 is maintained even after being removed from the molding dies 41, 42, the molded body 43 is removed from the molding dies 41, 42. The molded body 43 may be heated. When the

molds

41 and 42 are also heated together, it is preferable that the

molds

41 and 42 are made of a material having a melting point higher than that of the first biodegradable resin. The material may be, for example, a resin, a metal, or another material. In addition, when the molded body 43 is heated together with the

molds

41 and 42, the

molds

41 and 42 may be detached from the bone fixture 1 after the solidification step (step S103).

Further, when the third bone piece 23 exists between the first and

second bone pieces

21 and 22, a mold having the same shape as that of the third bone piece 23 may be manufactured. Then, a molded body having a shape that can be fitted to the first to third bone pieces 21 to 23 may be molded. Moreover, when the 3rd bone piece 23 exists between the 1st and

2nd bone pieces

21 and 22, but the shape of the 3rd bone piece 23 is unknown (for example, the 3rd bone piece 23) In the shape of the molded body, the portions corresponding to the third bone fragment 23 are located on both end surfaces of the first and second bone fragments 21 and 22. You may comprise by the cylindrical shape etc. which connect.

Further, as shown in FIG. 5A, the first biodegradable resin does not exist in a part of the length direction (left and right direction in the drawing) of the first and second

cylindrical portions

11 and 12. The

annular portions

51 and 52 made of the fibers of the second biodegradable resin may be provided. The

annular portions

51 and 52 are annular portions surrounding the internal cavity along the periphery of the side surfaces of the first and second

cylindrical portions

11 and 12. The locations where the

annular portions

51 and 52 are provided are not limited, but may be provided near the

openings

11a and 12a, for example. Since the

annular portions

51 and 52 are composed of fibers of the second biodegradable resin, the flexibility as the fibers is not lost even after the heating step and the solidification step. Therefore, as shown in FIG. 5B, when the first and

second bone pieces

21 and 22 are inserted into the first and second

cylindrical portions

11 and 12, at the locations of the

annular portions

51 and 52. The bone fixing device 1 may be tied to the first and second bone fragments 21 and 22 with the thread 53. Note that the bone fixing device 1 may be fixed to the first and second bone fragments 21 and 22 by restraining means other than the thread 53 (for example, a clip or the like). By doing so, the bone anchor 1 attached to the first and second bone fragments 21 and 22 can be prevented from shifting in the length direction (left and right direction in FIG. 5B). It is possible to prevent the fixture 1 from coming off. The restraining means such as the thread 53 is also preferably made of a biodegradable material. The thread 53 may be a silk thread, for example.

Moreover, in this Embodiment, although the bone fixing tool 1 was one cylindrical thing and mainly demonstrated the case where two bone fragments were fixed, in order to fix three or more bone fragments, May be used. In that case, for example, as shown in FIG. 1C and FIG. 1D, the bone anchor 1 includes a first tubular portion 11 into which the first bone fragment 21 is inserted and a second bone fragment 22. The second cylindrical part 12 to be inserted and the fourth cylindrical part 14 into which the fourth bone fragment 24 is inserted are provided, and they may be communicated with each other. 1C is a diagram showing a bone anchor 1 for fixing three bone fragments, and FIG. 1D is a diagram showing a state in which the bone fragments are inserted into the bone anchor 1. The fourth cylindrical portion 14 is the same as the first and second

cylindrical portions

11 and 12 and is composed of the above-described biodegradable fiber reinforced resin. By using such a bone fixing device 1, even when the bone is broken or cut at a branching point, each bone fragment can be fixed at that point, and bone healing is promoted. be able to. Moreover, you may make it fix N bone fragments with the bone fixing tool 1 provided with N cylindrical parts. N is an integer of 4 or more. Moreover, as shown in FIG. 1C, the bone anchor 1 having a branch may be manufactured, for example, by molding a cylindrical knitted body having a branch in (1) above.

As described above, according to the bone anchor 1 according to the present embodiment, the first and second bone fragments 21 and 22 that have been fractured or cut are fixed by the bone anchor 1. Both bone fusion will be promoted. Moreover, since the bone fixing tool 1 has a cylindrical shape into which a bone fragment is inserted, the possibility of the bone piece being detached from the bone fixing tool 1 when the bone piece is fixed can be reduced. The reason for this is, for example, that the bone fixing tool 1 has a larger contact area with the bone fragment than the joining pin, so that the bone fragment is less likely to be displaced, and the bone fixing tool 1 has a longer bone length than the joining pin. Since it can withstand the force in the direction orthogonal to the direction, it is difficult to form a gap between the bone pieces, and as a result, the bone pieces are unlikely to shift. Moreover, since the bone fixing tool 1 is non-invasive with respect to the bone fragment to be fixed, it can be elongated in the length direction within a range in which the bone fragment can be inserted. And since it becomes more difficult to remove a bone fragment when the longer bone anchoring tool 1 is used, it is considered that the bone anchoring tool 1 which is less likely to come off than the joining pin can be provided from that viewpoint. In addition, the joint pin cannot fix an osteoporotic bone piece or a thin bone piece, but when the bone fixing tool 1 is used, such a bone piece can also be fixed. Moreover, since the bone fixing tool 1 is comprised with the fiber reinforced resin, even if the force from the 1st and

2nd bone pieces

21 and 22 is applied, or the force from the outside is applied, it is hard to fracture | rupture. As a result, the bone can be properly fixed until the bone is fused. In addition, since the fiber reinforced resin is biodegradable, the bone fixing device 1 does not remain in the living body because it is decomposed and absorbed after a predetermined period of time without adversely affecting the living body. Therefore, it is not necessary to take out the bone anchor 1 from the living body after bone fusion. In addition, by forming the fiber reinforced resin of the bone fixing device 1 using the fibers having the first and second biodegradable resins, the molded body can be easily formed. Can be manufactured more easily.

Further, the present invention is not limited to the above-described embodiment, and various modifications are possible, and it goes without saying that these are also included in the scope of the present invention.

As described above, according to the bone fixing device or the like according to the present invention, an effect that the bone fragment to be fixed can be appropriately fixed is obtained, and it is useful as an instrument for fixing a bone fragment such as a rib.

Claims

A bone anchor used for fixing the first and second bone fragments to be fixed,
A first tubular portion into which the first bone fragment is inserted;
A second tubular portion connected to the first tubular portion, into which the second bone fragment is inserted, and
The first and second cylindrical portions include a matrix resin which is a first biodegradable resin, and reinforcing fibers of a second biodegradable resin having a melting point higher than that of the first biodegradable resin. A bone anchor composed of a fiber reinforced resin.
The bone anchor according to claim 1, wherein side surfaces of the first and second cylindrical portions have liquid permeability.
A gap corresponding to the third bone fragment exists between the first and second bone fragments,
A third cylindrical portion corresponding to the third bone fragment,
The first and second cylindrical portions are connected via the third cylindrical portion,
The bone fixing tool according to claim 1 or 2, wherein the third cylindrical portion is also composed of the fiber reinforced resin.
The bone fixing device according to claim 3, wherein the side surface of the third cylindrical portion has lower liquid permeability than the side surfaces of the first and second cylindrical portions.
The bone fixing tool according to any one of claims 1 to 4, wherein the first and second cylindrical portions are each formed into a shape that fits with the first and second bone fragments.
In a part of the first and second cylindrical portions in the length direction, the first biodegradable resin is not present, and an annular portion composed of fibers of the second biodegradable resin is provided. The bone anchor according to any one of claims 1 to 5, which is provided respectively.
The fiber reinforced resin heats the fiber having the first and second biodegradable resins at a temperature at which the first biodegradable resin melts and the second biodegradable resin does not melt. The bone anchor according to any one of claims 1 to 6, wherein
A method for producing a bone fastener used for fixing first and second bone fragments to be fixed,
A first tube into which the first bone fragment is inserted using a first biodegradable resin and fibers of a second biodegradable resin having a higher melting point than the first biodegradable resin. A molding step for molding a molded body having the same shape as the second cylindrical portion into which the second bone fragment is inserted, and the second cylindrical piece connected to the first cylindrical portion;
Heating the molded body at a temperature at which the first biodegradable resin is melted and the second biodegradable resin is not melted;
A solidification step of lowering and solidifying the temperature of the first biodegradable resin after the heating step;
Bone fixation having the first and second tubular parts, which is constituted by a fiber reinforced resin including a matrix resin which is the first biodegradable resin and a reinforced fiber of the second biodegradable resin. Manufacturing method of tool.
Further comprising the step of producing a mold having the same shape as the first and second bone fragments,
The method for manufacturing a bone fixing device according to claim 8, wherein in the molding step, a molded body having a shape to be fitted to the first and second bone fragments is molded using the molding die.
The method for manufacturing a bone anchor according to claim 8 or 9, wherein, in the molding step, the molded body is molded using fibers having the first and second biodegradable resins.