JP2010046283A - Implant material having fixing reliability toward defective bone part - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an implant material having fixing reliability which is used to fill a defective bone part as a bone filling material or a primary scaffold material and is fixed to the defective bone part so that the material does not fall off from the defective bone part. <P>SOLUTION: The implant material 100 having fixing reliability toward a defective bone part comprises a block-like implant material body 10 used to fill a defective bone part and a spring material 20 made of a biodegradable and bioabsorbable polymer and embedded within the implant material body 10 in such a way that ends 2a project from the surfaces of the implant material body 10. The spring material becomes compressed in the longitudinal direction when pressed in the longitudinal direction and returns to its original length when the pressure is released. When the implant material is used to fill a defective bone part, the ends 2a of the spring material 20 abut the inside of the defective bone part having concavities and convexities and catch the concavities and convexities. Alternatively, when a recessed hole is formed in advance on the inner surface of the defective bone part, the ends 2a of the spring material 20 fit in the recessed hole. By doing so, the implant material 100 is fixed to the defective bone part in such a way that the material does not fall off from the defective bone part. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention is a bone filling material (Bone Void Filler) for reconstructing a lost bone defect and its primary scaffolding material (Scaffolds), which is supplemented to the bone defect and fixed so as not to fall off. The present invention relates to an implant material having fixed reliability.

  In recent years, there has been considerable progress in medical material technology for filling and replacing large defects in soft tissue (subcutaneous, muscle) and hard tissue (cartilage, bone) with artificial materials or biological materials derived from living bodies. As one of such medical materials, the present applicant has a bioactive bioceramics powder particle uniformly dispersed in a biodegradable and absorbable polymer, and has continuous pores having a pore size of approximately 100 to 400 μm inside. An organic-inorganic composite porous body in which a part of the bioceramic powder particles is exposed on the surface and the inner surface of the pore has already been proposed (Patent Document 1).

This organic-inorganic composite porous material is an epoch-making new material that is expected to have various medical uses such as scaffolds for regeneration of living bone or cartilage tissue, bone filler, cancellous bone substitute, and drug release carrier. is there.
JP 2003-159321 A

  When the composite porous body of Patent Document 1 is filled in, for example, a defect part of a living bone to regenerate bone tissue, the composite porous body is cut according to the shape of the bone defect part, It is necessary to prevent it from falling off. However, since the composite porous body cannot be reliably fixed simply by cutting in accordance with the shape of the bone defect part, there is a possibility that the composite porous body may fall off from the bone defect part, and the fixing reliability to the bone defect part is insufficient. there were.

  In addition to the above composite porous bodies, bioceramic sintered bodies and metal porous bodies are known as implant materials used as bone fillers, etc., but these also lack fixed reliability. .

  The present invention has been made under the circumstances described above, and the problem to be solved is that the bone defect is replenished as a bone filler or a primary scaffold material for reconstructing the bone defect and is not dropped off. It is an object of the present invention to provide an implant material having a fixed reliability that is temporarily fixed.

  In order to solve the above-described problems, an implant material having a fixation reliability to a bone defect portion according to the present invention includes a block-shaped implant material body that is compensated for the bone defect portion, and an end portion from the surface of the implant material body. A spring made of a biodegradable absorbable polymer that is embedded in the implant material body in a protruding state, compressed in that direction when compressed in the length direction, and restored to its original length when released. And a material.

  In the implant material of the present invention, the spring material may penetrate the implant material main body, both ends of the spring material may protrude from the surface of the implant material main body, and the spring material is embedded in the surface layer portion of the implant material main body. In addition, one end of the spring material may protrude from the surface of the implant material body. Furthermore, the recessed part which fits the clamping piece of a jig | tool in the surface of an implant material main body may be formed, and the edge part of a spring material may protrude beyond the surface of an implant material main body from this recessed part.

  In the implant material of the present invention, a coil spring made of a biodegradable absorbable polymer is preferably used as the spring material, and the straight line memorized from the straight shape by being heated to the shape restoration temperature. A shape memory spring material of biodegradable absorbable polymer restored to a shape having coil spring portions at both ends of the portion is also used. The biodegradable absorbable polymer of the spring material includes poly-L-lactic acid, poly-D, L-lactic acid, a copolymer of L-lactic acid and D, L-lactic acid, and a copolymer of lactic acid and glycolic acid. Any one of a copolymer of lactic acid and p-dioxanone, a copolymer of lactic acid and ethylene glycol, a copolymer of lactic acid and caprolactone, or a mixture of two or more thereof may be used.

  In addition, the implant material main body may be any of a non-porous bioceramic sintered body, a porous bioceramic sintered body, a metal porous body, and a composite porous body of biodegradable absorbable polymer containing bioceramic powder particles. It may be.

  In the implant material of the present invention, the end portion of the spring material protruding from the surface of the block-shaped implant material main body is pressed with the holding piece of the jig and pushed into the implant material main body, and the implant material main body is held by the holding piece to The bone defect portion is compensated by fitting into the defect portion and pulling out the holding piece of the jig from the bone defect portion. When the implant material is thus supplemented to the bone defect portion, the spring material is restored, the end portion of the spring material protrudes from the surface of the implant material body, and the end portion of the spring material is pressed against the inner surface of the uneven bone defect portion. Therefore, the implant material is fixed to the bone defect portion, and the fear of dropping off is eliminated. In that case, if a depression hole into which the end portion of the spring material fits in the inner surface of the bone defect portion is formed in advance, the end portion of the spring material fits into the depression hole and the implant material is fixed more reliably. It will be. And the spring material made of biodegradable absorbable polymer is not harmful to living bones as seen in metal springs, it is in contact with bodily fluids and hydrolysis proceeds, and the implant material body is bone tissue When it is fixed to the bone defect by growth, it is absorbed into the living body and disappears.

  In the implant material of the present invention, a recess in which a holding piece of a jig is fitted is formed on the surface of the implant material body, and the end of the spring material protrudes beyond the surface of the implant material body from the recess. Since the clamping piece of the jig for pressing the end of the material to clamp the implant material body fits into the recess and does not come out of the surface of the implant material body, the inner surface of the bone defect and the surface of the implant material body Even if there is no gap corresponding to the thickness of the sandwiching piece between them, the implant material can be supplemented to the bone defect portion. Accordingly, since the gap between the inner surface of the bone defect portion and the surface of the implant material body can be reduced, this slight gap is filled in a relatively short period of time by the growing bone tissue, and the implant material body is surrounded and fixed by the bone tissue. Will come to be.

  As a spring material, an implant material using a coil spring made of a biodegradable absorbable polymer, when pressed with a clamping piece of a jig, the entire length of the coil spring is shortened and pushed into the implant material body, Implant materials using biodegradable absorbable polymer shape memory spring material restored to a shape having coil springs at both ends of the straight line portion memorized from the straight shape are long at the coil spring portions at both ends when compressed in the same way. The length of the spring material is shortened and pushed into the implant material body.Each spring material expands and recovers when the compression by the clamping piece is released, and the end of the spring material protruding from the surface of the implant material body is the inner surface of the bone defect portion. It can be caught in the irregularities and prevent the implant material from falling off the bone defect. In particular, the implant material using the latter shape memory spring material is inserted into the implant material body in a linear shape, and then heated to a shape restoration temperature to restore both ends to a coil spring shape. There is an advantage that a spring material can be attached to the through hole (through hole through which the coil spring portion cannot be inserted) of the implant material main body having a slightly larger diameter.

  In the implant material of the present invention, as described above, the spring material may penetrate the implant material main body and both ends of the spring material may protrude from the surface of the implant material main body. One end of the spring material may protrude from the surface of the implant material body embedded in the surface layer, but the latter uses the former configuration because the number of spring materials is twice that of the former and the number of parts increases. Is preferred.

  In addition, as described above, the implant material main body is a composite of a non-porous bioceramic sintered body, a porous bioceramic sintered body, a porous metal body, and a biodegradable absorbable polymer containing bioceramic powder particles. In particular, when a composite porous body of biodegradable absorbable polymer containing bioceramics particles is used, the composite porous body and the inner surface of the bone defect portion will be described later. There is an advantage that the bone tissue can be regenerated in the bone defect portion by binding at an early stage and finally replacing the bone tissue.

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

  FIG. 1 is a perspective view of an implant material according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line AA of FIG. 3 to 5 sequentially illustrate the usage of the implant material, and FIG. 3 is a cross-sectional view showing a state in which the implant material before being inserted into the bone defect portion is clamped by a clamping piece of a jig. Fig. 5 is a cross-sectional view showing a state in which the implant material clamped by the clamping piece of the jig is fitted in the bone defect portion, and Fig. 5 shows a state in which the clamping material is pulled out and the implant material is compensated in the bone defect portion. It is sectional drawing.

  As shown in FIGS. 3 to 5, the implant material 100 is supplemented in the bone defect 31 as a bone filler for reconstructing the bone defect 31 of the living bone 30. As shown in FIG. 2, it is comprised by the block-shaped implant material main body 10 and the two spring materials 20 and 20. As shown in FIG.

  The implant material body 10 to be filled in the bone defect portion 31 is composed of a composite porous body of a biodegradable and absorbable polymer containing bioactive bioceramics particles, and this composite porous body has continuous pores therein. A part of the bioceramic powder particles is exposed on the surface of the composite porous body and the inner surface of the pores. In this embodiment, the implant material main body 10 made of the composite porous body is formed in a substantially rectangular parallelepiped shape that substantially matches the shape of the bone defect portion 31, and the implant material main body 10 is cured as shown in FIG. A gap is secured between the surface of the implant material main body 10 and the inner surface of the bone defect 31 when the clip 40 is sandwiched between the clamps 41 and 41 of the tool 40 and fitted into the bone defect 31. As described above, the vertical dimension of the implant material main body 10 is smaller than the vertical dimension of the bone defect portion 31 by at least the thickness dimension of the sandwiching pieces 41, 41. Needless to say, the shape of the implant material body 10 is not limited to a substantially rectangular parallelepiped shape as in this embodiment, and may be various block shapes depending on the shape of the bone defect portion.

  As shown in FIG. 2, the implant material main body 10 has two through holes 1 a and 1 a for penetrating the main body 10 for vertically inserting the spring material. And the spring material 20 is penetrated by each through-hole 1a, and the both ends 2a and 2a of each spring material 20 have protruded from the upper and lower surfaces of the implant material main body 10. FIG.

  Said composite porous body which comprises the implant material main body 10 is produced by the following method (spray method). First, the biodegradable absorbent polymer is dissolved in a volatile solvent, and bioceramics particles are mixed to prepare a suspension. The suspension is made into a fiber by means of spraying or the like, and a fiber assembly in which fibers are intertwined Form the body. Next, this fiber assembly is immersed in a volatile solvent such as methanol, ethanol, isopropanol, dichloroethane (methane), chloroform, etc. to be in a swollen or semi-dissolved state, and this is pressurized to form a substantially rectangular parallelepiped porous fiber fusion. While forming into an aggregate and shrinking and fusing the fibers of this fiber fusion aggregate, the fiber form is substantially lost to form a matrix, and the porous matrix has continuous pores with rounded voids between fibers. While changing the form, a part of the bioceramic powder particles is exposed on the inner surface and the surface of the pores to obtain a substantially rectangular parallelepiped composite porous body having no through-hole 1a. Finally, the composite porous body is cut (perforated) to form the through holes 1a and 1a, thereby producing the composite porous body.

  As a biodegradable and absorbable polymer of a composite porous body, it is safe, relatively quick to decompose, and is not brittle even if it becomes a porous body, amorphous or a mixture of crystalline and amorphous poly-D, L-lactic acid, L-lactic acid and D, L-lactic acid copolymer, lactic acid and glycolic acid copolymer, lactic acid and p-dioxanone copolymer, lactic acid and ethylene glycol copolymer, lactic acid and caprolactone copolymer, etc. These are used alone or in combination of two or more. These polymers are preferably those having a viscosity average molecular weight of about 50,000 to 1,000,000 considering the ease of forming a fiber aggregate by fiberization and the period of degradation and absorption in vivo.

  Bioceramics particles are bioactive, bioresorbable, completely replaced with bone tissue, and have good osteoinductive or osteoconductive properties and good biocompatibility. Powdered particles of calcined hydroxyapatite, dicalcium phosphate, tricalcium phosphate, tetracalcium phosphate, octacalcium phosphate, calcite, serabital, diopsite, smallpox, etc. are preferably used. And what adhered the alkaline inorganic compound and the basic organic substance to the surface of these powder particles can also be used. Among these, uncalcined and uncalcined hydroxyapatite, tricalcium phosphate, and octacalcium phosphate have extremely high bioactivity, excellent osteoinductive ability or osteoconductivity, low toxicity, and absorption in the living body in a short period of time. Therefore, it is very preferably used.

  The bioceramic powder particles have a particle size of about 30 μm or less, preferably about 10 μm or less, more preferably about 0.1 to 5 μm, considering dispersibility in the biodegradable absorbent polymer and absorbability to the living body. Things are used. In particular, bioceramic powder particles having a particle size of about 0.1 to 5 μm are formed when a composite porous body is produced by the spray method described above in addition to good absorbability to living bodies. It is preferably used because there is no fear of cutting the fiber short.

  The content of the bioceramic powder in the composite porous body is preferably 50 to 90% by mass. When the implant material body 10 composed of the composite porous body having such a content is filled in the bone defect portion 31, Due to the osteoinductive ability or the osteoconductive ability, the bone tissue is promptly formed to the inside of the composite porous body, and it is completely replaced with the composite porous body in a relatively short period of time. If the content of bioceramics particles is less than 50% by mass, the time required for the composite porous body to completely replace the bone tissue becomes longer. If it exceeds 90% by mass, a composite porous material is produced by the spray method described above. In doing so, the biodegradable absorbent polymer fibers containing the bioceramic powder particles are disadvantageous in that they can be cut short.

  The composite porous body constituting the implant material body 10 has a porosity of 50 to 90%, continuous pores account for 50 to 100% of the total pores, and the pore size of the continuous pores is 40 to 600 μm. It is preferable that it is adjusted. The porosity, the ratio of continuous pores, the pore diameter, etc. are adjusted by applying the fiber density of the fiber assembly, the fiber thickness, and the fiber assembly when the composite porous body is prepared by the spray method described above. This can be done by controlling the pressure at the time of forming the fiber fusion aggregate. Further, the composite porous body obtained by the above-mentioned spray method has small pores having a pore diameter of 1 μm or less in the pore walls of the continuous pores in addition to the above-mentioned continuous pores having a large pore diameter. It is also preferable that some are continuous and such small pores coexist.

  The implant material body 10 composed of a composite porous body having the above-mentioned porosity, the ratio occupied by continuous pores, and the pore diameter is not brittle and has sufficient initial physical strength necessary as a bone filler, resulting in a bone defect. When the portion 31 is supplemented, the body fluid and osteoblasts enter the inside of the composite porous body, and the hydrolysis and the growth of the bone tissue are performed promptly. If the porosity of the composite porous body is less than 50%, the continuous pores are less than 50% of the total pores, and the pore diameter of the continuous pores is smaller than 40 μm, the invasion of body fluids and osteoblasts into the composite porous body is reduced. It is not preferable because hydrolysis of the composite porous body and growth of the bone tissue are slowed, and the period required for the composite porous body to completely replace the bone tissue and regenerate the bone defect portion 31 becomes long. On the other hand, if the porosity of the composite porous body exceeds 90% and the pore diameter is larger than 600 μm, the physical strength of the composite porous body decreases and becomes brittle, which is inappropriate as a bone filler. The more preferable pore diameter of the continuous pores is 100 to 400 μm.

  In particular, when a part of small pores having a pore diameter of 1 μm or less continues to a part of large continuous pores, hydrolysis proceeds rapidly from both the inner surface of the large continuous pores and the inner surface of the small pores by the invading body fluid. Moreover, since osteoblasts that have entered through the continuous pores are fixed to the small pores and actively proliferated and differentiated, there is an advantage that the bone tissue is regenerated more quickly. That is, the preferable pore diameter range of the small pores is 0.05 to 1 μm, and the more preferable pore diameter range is 0.1 to 1 μm in view of osteoconductivity and osteoinductivity.

  The through hole 1a formed in the implant material body 10 made of the composite porous body is preferably a hole having a minimum diameter through which the spring material 20 can be inserted. The through-hole 1a is finally filled with a growing bone tissue. However, the larger the diameter of the through-hole 1a, the longer the period until it is filled with the bone tissue. It is preferable to shorten the period as much as possible. The specific diameter of the through hole 1a varies depending on the outer diameter and type of the spring material. However, when the spring material 20 is a coil spring as in the present embodiment, the diameter of the through hole 1a is considered in consideration of the coil outer diameter. Is 10 mm or less, preferably 8 mm or less, and when the spring material is a shape memory spring material 22 having coil spring portions at both ends of the straight portion described later, the wire diameter (diameter) of the straight portion In consideration of the above, the diameter of the through hole 1a should be 1.5 mm or less, preferably 1 mm or less.

  The spring material 20 inserted through the through hole 1a of the implant material body 10 is a cylindrical coil spring made of a biodegradable and absorbable polymer, and as shown in FIG. 2, both ends 2a and 2a thereof are implant materials. The coil spring protrudes from both the upper and lower surfaces of the main body 10 and is compressed in that direction when compressed in the length direction and restored to the original length when the compression is released. Then, as shown in FIG. 5, when the implant material body 10 is fitted into the bone defect portion 31 to be compensated, both end portions 2a and 2a of the coil spring 20 are pressed against the upper and lower inner surfaces of the bone defect portion 31 and the upper and lower inner surfaces are uneven. In addition, when a depressed hole (not shown) is formed in advance on the upper and lower inner surfaces of the bone defect portion 31, the implant material is fitted into both the end portions 2a and 2a of the coil spring 20 in the depressed hole. The main body 10 is fixed to the bone defect portion 31 so as not to fall off.

  The coil spring 20 is a monofilament 1a obtained by stretching a biodegradable absorbent polymer into a cylindrical coil shape having a constant average coil diameter. The monofilament of biodegradable absorbable polymer is stretched 2 to 9 times at a temperature lower than its melting point and 100 ° C. or higher to obtain a monofilament 1a having a diameter of 0.1 mm or more and less than 1.2 mm, and this stretched monofilament To a rotating core at a temperature not lower than the glass transition temperature (Tg) and not higher than the crystallization temperature (Tc) (for example, 100 ° C. or lower in the case of amorphous such as poly-D, L-lactic acid and no crystallization temperature). A coil spring obtained by winding and quenching.

  Examples of the biodegradable absorbable polymer used as the material of the coil spring 20 include poly-L-lactic acid, poly-D, L-lactic acid, a copolymer of L-lactic acid and D, L-lactic acid, which are safe for the living body, A copolymer of lactic acid and glycolic acid, a copolymer of lactic acid and p-dioxanone, a copolymer of lactic acid and ethylene glycol, or a copolymer of lactic acid and caprolactone is used alone or in a mixture of two or more. Among these, crystalline poly-L-lactic acid is particularly preferably used because it can be stretched to moderately increase the crystallinity to obtain a coil spring 20 having a high toughness and a high compressive strength. In addition, polymers other than poly-L-lactic acid are relatively quick decomposition, elastic and not brittle, and are amorphous or a mixture of crystal and amorphous, so the compressive strength is not so high and It is suitably used as a material for a flexible coil spring that can be decomposed and absorbed in the body in a relatively short period of time, or as a material for a shape memory spring material 22 described later. The viscosity average molecular weight (Mv) of the polymer is about 50,000 to 400,000 for poly-L-lactic acid, and about 30,000 to 100,000 for other cases, considering the strength of the coil spring 20 and the speed of decomposition and absorption. It is preferable that

  The diameter of the monofilament composing the coil spring 20 is preferably 0.1 mm or more and less than 1.2 mm as described above in consideration of use in a living body. If the strength is insufficient and the thickness is larger than 1.2 mm, a coil spring having a large average coil diameter that is unsuitable for fixing the implant material main body 10 is produced, resulting in inconveniences such as a longer period of time for decomposition and absorption. A more preferable diameter of the monofilament of the coil spring 20 is 0.3 to 0.6 mm.

  Further, the stretching ratio of the monofilament of the coil spring 20 is preferably 2 to 9 times as described above in order to increase the toughness, and the toughness is not improved so much at a stretching ratio of less than 2 times, while the stretching is performed. When the magnification is larger than 9 times, the polymer molecules and crystals are excessively oriented and fibrillated, and there is a concern that the living tissue is damaged or inflamed. A more preferable draw ratio of the monofilament of the coil spring 20 is 3 to 5 times.

  When a monofilament made of crystalline poly-L-lactic acid is stretched, the degree of crystallinity increases, but if the degree of crystallinity becomes too high, it becomes a hard and brittle monofilament and it becomes difficult to obtain a tough coil spring 20. The crystallinity is preferably 75% or less. If the draw ratio is 9 times or less as described above, the crystallinity will be 75% or less. A more preferable crystallinity is 60% or less.

  The spring index (coil average diameter / monofilament diameter) of the coil spring 20 is preferably set to 3.5 to 7. A coil spring having a spring index smaller than 3.5 is too hard and is strongly compressed in the coil length direction. Then, it becomes easy to break. On the other hand, a coil spring having a spring index greater than 7 has the disadvantage that it becomes too soft and expands and contracts in the coil length direction due to its own weight, and the coil average diameter becomes too large, so it is not suitable for fixing the implant material body 10. Coil spring.

  The coil pitch of the coil spring 20 is not particularly limited, but the coil spring 20 that fixes the implant material body 10 to the bone defect portion 31 needs to be considerably compressed and restored in the coil length direction. Is preferably set to 2 to 3 times.

  The coil spring 20 has a natural length such that both end portions 2a and 2a protrude from the upper and lower surfaces of the implant material body 10 to be larger than the thickness dimension of the holding pieces 41 and 41 of the jig 40, specifically Is preferably used with a natural length such that both end portions 2a, 2a protrude from the upper and lower surfaces of the implant material body 10 by about 1.5 to 5 mm. The coil spring 20 having a short natural length so that both end portions 2a and 2a do not protrude 1.5 mm from the upper and lower surfaces of the implant material body 10 is obtained when the bone defect 31 is filled with the implant material body 10. Both end portions 2a, 2a are substantially pressed against the upper and lower inner surfaces of the bone defect portion 31 and are hardly caught by the irregularities on the upper and lower inner surfaces, and depressions are formed in the upper and lower inner surfaces of the bone defect portion 31. Since the upper end 2a of the coil spring 20 hardly fits into the recessed hole on the upper surface, it is difficult to eliminate the possibility that the implant material body 10 will fall off the bone defect 31. On the other hand, the coil spring 20 having a long natural length in which both end portions 2a and 2a protrude beyond 5 mm from the upper and lower surfaces of the porous body 1 has both end portions 2a and 2a of the coil spring 20 at the clamping pieces 41 and 41 of the jig 40. It is difficult to sandwich the implant material main body 10 while compressing it from above and below and pushing it into the through-hole 1a, and the end 2a of the coil spring 20 that protrudes greatly from the implant material main body 10 when bent is bent or broken. After all, it is not preferable.

  The coil spring 20 is imparted with bioactivity by spraying the above-described bioactive bioceramic powder particles, and promotes the formation (conduction) of bone tissue, thereby promptly forming the inner surface of the bone defect 31 and the spring end. It is preferable to achieve coupling with the portion 2a. The spraying of the bioceramic powder particles may be performed on at least both end portions 2 a and 2 a of the coil spring 20, but it is preferable to perform the spraying on the entire coil spring 20. When bioceramic powder particles are sprayed on the entire coil spring 20, the bone tissue is guided to the coil spring 20 and promptly induced (conducted) inside the through hole 1a of the implant material body 10, so that the through hole 1a is formed into the bone. There is an advantage that the period of regeneration in the organization can be shortened.

  The spraying of the bioceramic powder particles is performed, for example, by the following method. When spraying the entire coil spring 20, the coil spring 20 is installed in a closed space heated to 70 to 100 ° C., and the bioceramic powder particles are placed on a metal net having a finer mesh than the bioceramic powder particles. And installed below the coil spring 20. When the coil spring 20 and the bioceramic powder particles are heated, when air heated to 100 to 130 ° C. is blown using a dryer or the like, the bioceramic powder particles pierce the surface layer of the coil spring 20 and do not peel off. To adhere. If necessary, this operation is repeated several times to adjust the amount of bioceramic powder particles adhering. Note that the bioceramic powder particles that are simply stuck without being pierced to the surface layer are washed away with ethanol, water, or the like, thereby completing the spraying process in which the bioceramic powder particles are not easily detached.

  On the other hand, when the bioceramic powder particles are sprayed on both ends 2a, 2a of the coil spring 20, the coil spring 20 is inserted into the single through hole 1a of the implant material body, and the metal with the bioceramic powder particles placed on the lower side thereof. After installing the net and heating in the same manner as above, the bioceramics powder is sprayed on the spring ends 2a, 2a and the surrounding area with a drier etc., and the bioceramics particles are pierced on the surface layer of the spring ends 2a, 2a. To attach. In this way, the bioceramic powder particles also adhere to the surface of the implant material body 10 around the spring ends 2a, 2a. However, this bioceramic powder particles promote the formation (conduction) of bone tissue and implant. This is advantageous because it acts to speed up the connection between the material body 10 and the bone defect 31.

  The coil spring 20 is preferably coated with a biodegradable absorbent polymer composite containing bioactive bioceramic particles instead of spraying bioceramic particles. When coated in this way, bioactivity is promoted and expressed by the ceramic particles that are gradually released as the biodegradable polymer is decomposed, and conduction (induction) formation of bone tissue is promoted, resulting in early bone defect. The inner surface of 31 and the spring end 2a are joined. The coating may be applied to at least both ends 2a and 2a of the coil spring 20. However, when the entire coil spring 20 is coated, bone tissue is guided to the coil spring 20 and promptly guided (conducted) into the through hole 1b. There is an advantage that the period in which the through-hole 1b is formed and regenerated with bone tissue can be shortened.

  As a means for coating the coil spring 20, a suspension is prepared by dissolving the biodegradable absorbent polymer in a volatile solvent such as ethanol, dichloroethane (methane), and chloroform and mixing the bioceramics particles uniformly. The suspension is applied to both ends 2a, 2a or the whole of the coil spring 20, or sprayed (sprayed), or both ends 2a, 2a or the whole of the coil spring 20 are applied to the suspension. Means such as immersion are employed.

  Biodegradable absorbable polymers for coating include poly-D, L-lactic acid, a copolymer of amorphous or crystalline and amorphous, a copolymer of L-lactic acid and D, L-lactic acid, and lactic acid and glycolic acid. Suitable are copolymers, copolymers of lactic acid and p-dioxanone, copolymers of lactic acid and ethylene glycol, copolymers of lactic acid and caprolactone, and these are used alone or in admixture of two or more. Is done. Although the molecular weight of these polymers is not limited, those having a viscosity average molecular weight of about 30,000 to 100,000 are preferably used in consideration of the strength of the coating film and the speed of decomposition and absorption.

  The content of bioceramic particles in the biodegradable polymer composite is preferably 50 to 90% by volume, and if included within this range, the bioconductivity or osteoinductivity of the bioceramics particles The bone tissue is promptly conducted (induced) to the spring end 2a, and is quickly bonded to the inner surface of the bone defect 31 and fixed. The more preferable content of the bioceramic powder is 60 to 80% by volume.

  The implant material 100 having the above-described configuration is filled in the bone defect portion of the living bone 30 in the following manner so as not to fall off. First, as shown in FIG. 3, the coil spring 20 of the implant material 100 is pressed from above and below with the sandwiching pieces 41, 41 at the tip of the jig 40, and the spring both ends 2 a, 2 a are inserted into the through holes 1 a of the implant material body 10. The implant material main body 10 is clamped while being pushed in. Then, as shown in FIG. 4, the implant material main body 10 is inserted into the bone defect 31 of the living bone 30 while being sandwiched by the sandwiching pieces 41, 41 of the jig 40, and the jig sandwiching piece as shown in FIG. Is pulled out and the implant material body 10 is fitted into the bone defect 31.

  When the implant material body 10 is fitted into the bone defect portion 31 in this way, the coil spring 20 is restored and expanded as shown in FIG. 5, and both end portions 2 a and 2 a of the spring are pressed against the upper and lower inner surfaces of the bone defect portion 31. . Although this bone defect portion 31 has been reduced in advance, the inner surface of the bone defect portion 31 is not a perfect plane as shown in FIG. Both ends 2a and 2a of the spring that are in pressure contact with each other are caught by the projections and depressions, whereby the implant material body 10 is fixed to the bone defect 31 so as not to fall off and is compensated. Therefore, this implant material 100 is excellent in fixing reliability. In addition, if a recessed hole (not shown) in which both ends 2a, 2a of the coil spring 20 are fitted in advance is formed on the inner surface of the bone defect portion 31, the spring both ends 2a, 2a are fitted in the recessed hole. As a result, the implant material body 10 can be more reliably fixed.

  Implant material body 10 filled in bone defect part 31, that is, a composite porous body of biodegradable absorbable polymer containing bioceramics particles, rapidly penetrates into the interior through continuous pores from the surface. In addition, hydrolysis of the biodegradable absorbent polymer proceeds from both the surface and the inside of the composite porous body. Then, with this hydrolysis, bone tissue is induced (conducted) in the surface layer portion of the composite porous body by the bioceramic powder particles exposed on the surface of the composite porous body, and the composite porous body (implant material body 10) becomes a bone defect. In addition to the early bonding with the inner surface of the part 31, the bone tissue is induced (conducted) to the inside of the composite porous body by the bioceramics particles exposed on the inner surface of the pores, finally replacing the composite porous body, The composite porous body (implant material body 10) disappears, and the bone tissue is regenerated in the bone defect portion 31.

  In addition, bioactive bioceramics particles are sprayed on both ends 2a, 2a of the coil spring 20, or both end portions 2a, 2a of the coil spring 20 are biodegradable absorbent polymer containing bioactive bioceramics particles. When coated with the composite, as described above, the bone tissue is immediately formed (conducted) at both ends 2a, 2a of the coil spring 20, and the both ends 2a, 2a of the spring are bone defects. It couple | bonds with the inner surface of the part 31. FIG. Then, when bioceramic powder particles are sprayed on the entire coil spring 20 or the entire coil spring 20 is coated with a biodegradable and absorbable polymer composite, both ends 2a and 2a of the spring are quickly removed from the bone defect 31. In addition to being coupled to the inner surface of the bone material, the bone tissue is guided to the through-hole 1a of the implant material body 10 in a relatively short period of time by being guided to the coil spring 20, so that the through-hole 1a is formed by the bone tissue. The time until filling is shortened.

  The implant material 100 of the above embodiment forms two through-holes 1a and passes through two coil springs 20, but forms one or three or more through-holes 1a and one or three or more. It goes without saying that the coil spring 20 may be inserted.

  FIG. 6 is a cross-sectional view of an implant material 101 according to another embodiment of the present invention.

  This implant material 101 is formed with two bottomed holes 1b on the upper and lower surface layers of the implant material main body 11, and a cylindrical coil spring 21 having a short coil length is formed as a spring material in each hole. The end portions 2a of the respective coil springs 21 are protruded from both the upper and lower surfaces of the implant material body 11 by being embedded partway in the portion 1b.

  The implant material main body 11 of the implant material 101 is composed of a composite porous body of biodegradable absorbable polymer containing bioceramics particles, like the implant material main body 10 of the implant material 100 described above. Since it is made of a biodegradable absorbable polymer in the same manner as the coil spring 20 described above, a duplicate description thereof will be omitted.

It goes without saying that such an implant material 101 also has the same operational effects as the above-described implant material 100 and has fixing reliability.
As the spring material, instead of the cylindrical coil spring 21 described above, a conical short coil spring whose coil diameter gradually increases from one end to the other end is used, and the surface layer portion of the implant material main body 11 is used. The conical coil spring may be embedded in each hole 1b, and the spring end portion having the smaller coil diameter may protrude from the surface of the implant material body 11.

  In the implant material of the present invention, the spring material (coil spring) 20 penetrates the implant material main body 10 up and down like the implant material 100 of the above-described embodiment, and both ends 2a and 2a of the spring material 20 are the implant material main body 10. Further, a spring material (short coil spring) 21 is embedded in the upper surface side and the lower surface side of the implant material main body 11 like the implant material 101 of the embodiment described above. The end portion 2a of the spring material 21 may protrude from both the upper and lower surfaces of the implant material body 11, but the latter implant material 101 has twice the number of the spring material 21 and the number of parts increases. It is preferable to let the spring material 20 penetrate the implant material main body 10 like the former porous implant material 100. .

  7 is a perspective view of an implant material according to still another embodiment of the present invention, FIG. 8 is a cross-sectional view taken along line BB of FIG. 7, and FIG. FIG. 10 is a cross-sectional view showing a state in which the implant material is compensated in a bone defect part.

  In this implant material 102, a pair of shallow recesses 1c, 1c for receiving the sandwiching pieces 41, 41 of the jig 40 are formed on the upper and lower surfaces of the block-shaped implant material body 12, and these recesses 1c, 1c are formed in the implant material 102. A through hole 1a for inserting a spring material that communicates vertically is formed. A cylindrical coil spring 20 is inserted as a spring material into the through-hole 1a, and both end portions 2a and 2a protrude from the upper and lower recesses 1c and 1c beyond both the upper and lower surfaces of the implant material body 12.

  The implant material body 12 is composed of a composite porous body of biodegradable absorbable polymer containing bioceramics powder particles, similar to the implant material body 10 of the implant material 100 described above, and the coil spring 20 also includes the implant material described above. Since it is made of a biodegradable and absorbable polymer as in the case of 100 coil springs 20, overlapping description thereof will be omitted.

  As shown in FIG. 9, such an implant material 102 presses the coil spring 20 from above and below by the clamping pieces 41 and 41 at the tip of the jig 40 and holds the implant material main body 12 at the upper and lower recesses 1 c and 1 c. The surface of the implant material body 12 is substantially in contact with the inner surface of the bone defect portion 31 as shown in FIG. 10 by being inserted into the bone defect portion 31 of the living bone 30 as it is and pulled out. In this state, both end portions 2a and 2a of the coil spring 20 that have been compensated, restored, and expanded by the bone defect portion 31 are fixed so as not to be dropped from the bone defect portion 31 by being caught by the irregularities on the upper and lower inner surfaces of the bone defect portion 31. In particular, when the implant material main body 12 is clamped by the clamp pieces 41 and 41 of the jig 40, the implant material 102 is fitted into the concave portions 1c and 1c, and the surface of the implant material main body 12 excluding the concave portions is formed. Since the implant material main body 12 can be supplemented to the bone defect portion 31 so that a gap is not substantially formed between the inner surface of the bone defect portion 31 and bone tissue is induced (conductive) on the surface of the implant material main body 12 at an early stage. Has the advantage of being directly coupled and fixed.

  FIG. 11 is a cross-sectional view of an implant material according to still another embodiment of the present invention, FIG. 12 is an explanatory view of a shape memory spring material used for the implant material, and (a) shows the shape before shape restoration. , (B) shows the shape after shape restoration.

  In the implant material 103, holes 1b and 1b are formed in the upper and lower surface layers of the implant material body 13, and through holes 1d having small diameters communicating the upper and lower holes 1b and 1b are drilled. Yes. The linear portion 22a of the shape memory spring material 22 is inserted through the through hole 1d, and the coil spring portions 22b and 22b at both ends of the shape memory spring material 22 are embedded in the upper and lower holes 1b and 1b by about half. The end portions of the coil spring portions 22 b and 22 b protrude from both the upper and lower surfaces of the implant material main body 13.

  This shape memory spring material 22 is heated to a shape restoration temperature, and the coil spring portion is then applied to both ends of the linear portion 22a shown in FIG. 12 (b) from the linear shape shown in FIG. 12 (a). This is a biodegradable absorbable polymer spring material restored to a shape having 21a and 21a. That is, the shape memory spring material 22 is made of a metal in which both end portions of a monofilament obtained by extruding the above-described biodegradable absorbent polymer (excluding poly-L-lactic acid) at a melting point or higher are heated to 100 to 130 ° C. Was formed into a spring shape having coil spring portions 22b and 22b at both ends of a linear portion 22a as shown in FIG. 12B, and cooled to room temperature as it was to store the spring shape. Thereafter, this is stretched to a linear shape shown in FIG. 12 (a) at a temperature slightly higher than the glass transition point of the polymer and cooled to room temperature as it is to fix the linear shape. By inserting the through hole 1d having a small diameter into a through hole 1d and heating it to a shape restoration temperature slightly higher than the above-described stretching temperature, the memory shown in FIG. The shape is restored, and the coil spring portions 22b and 22b are accommodated in the holes 1b and 1b so that the ends of the coil spring portions 22b and 22b at both ends of the linear portion 22a protrude from the upper and lower surfaces of the implant material body 13. It is a thing. When the shape memory spring material 22 is compressed in the length direction by the clamping piece of the jig, the coil spring portions 22b and 22b at both ends of the linear portion 22a are pressed and contracted to shorten the overall length of the spring material 22. When the compression is released, the coil spring portions 22b and 22b at both ends are restored and pressed against the inner surface of the bone defect portion, and are caught by the unevenness of the inner surface so that the implant material 103 can be fixed.

  Since the implant material body 13 of the implant material 103 is composed of a composite porous body of a biodegradable absorbable polymer containing bioceramic powder particles, similar to the implant material body 10 of the implant material 100 described above, Description is omitted.

  Such an implant material 103 has a fixing reliability like the above-described implant materials 100, 101, 102, and in addition, there is a concern that the shape memory spring material 22 may fall off during handling before filling the bone defect. In addition, since the diameter of the through hole 1d is small, there is an advantage that the through hole 1d is filled with bone tissue at an early stage.

  The implant materials 100, 101, 102, 103 according to the above-described embodiments are composed of a composite porous body of biodegradable absorbable polymer in which the implant material bodies 10, 11, 12, 13 all contain bioactive bioceramic powder particles. However, the implant material bodies 10, 11, 12, and 13 are not limited to such composite porous bodies, and are non-porous bioceramic sintered bodies and porous bioceramics sintered bodies. It may consist of a knot or a porous metal body.

  Preferred examples of non-porous or porous bioceramic sintered bodies include non-porous sintered bodies such as hydroxyapatite (HA) and α- or β-tricalcium phosphate (α- or β-TCP). And porous sintered bodies, and preferable examples of the metal porous body include porous bodies such as titanium and tantalum.

It is a perspective view of the implant material which concerns on one Embodiment of this invention. It is the sectional view on the AA line of FIG. It is sectional drawing which shows the state which clamped the implant material before filling a bone defect part with the clamping piece of a jig | tool. It is sectional drawing which shows the state which inserted the same implant material clamped with the clamping piece of the jig | tool at the bone defect part. It is sectional drawing which shows the state which pulled out the clamping piece of the jig | tool and supplemented the implant material to the bone defect part. FIG. 6 is a cross-sectional view of an implant material 101 according to another embodiment of the present invention. It is a perspective view of the implant material which concerns on other embodiment of this invention. It is the BB sectional view taken on the line of FIG. It is sectional drawing which shows the state which clamped the implant material before filling a bone defect part with the clamping piece of a jig | tool. It is sectional drawing which shows the state which filled the bone defect part with the implant material. It is sectional drawing of the implant material which concerns on other embodiment of this invention. It is explanatory drawing of the shape memory spring material used for the implant material, Comprising: (a) shows the shape before shape restoration, (b) shows the shape after shape restoration.

Explanation of symbols

100, 101, 102, 103 Implant material 10, 11, 12, 13 Implant material main body 1a Through hole 1b Hole 1c Recess 1d Small diameter through hole 20, 21 Coil spring (spring material)
22 Shape memory spring material 2a End portion of spring material 22a Linear portion of shape memory spring material 22b Coil spring portion of shape memory spring material 30 Living bone 31 Bone defect 40 Jig 41 Jig clamping piece

Claims (8)

A block-shaped implant material body to be filled in the bone defect,
It is embedded in the implant material body with its end protruding from the surface of the implant material body, compressed in that direction when compressed in the length direction, and restored to its original length when the compression is released. A spring material made of a degradable absorbent polymer;
An implant material having a reliability of fixing to a bone defect portion.   The implant material according to claim 1, wherein the spring material penetrates the implant material body, and both end portions of the spring material protrude from the surface of the implant material body.   The implant material according to claim 1, wherein the spring material is embedded in a surface layer portion of the implant material main body, and one end portion of the spring material protrudes from the surface of the implant material main body.   4. A recessed portion into which a clamping piece of a jig is fitted is formed on the surface of the implant material body, and an end of the spring material protrudes beyond the surface of the implant material body from the recessed portion. The implant material as described.   The implant material according to any one of claims 1 to 4, wherein the spring material is a coil spring made of a biodegradable polymer.   The spring material is a biodegradable absorbable polymer shape memory spring material that is restored from a linear shape to a shape having coil spring portions at both ends of the stored linear portion by being heated to a shape restoration temperature. The implant material according to claim 1, claim 2, or claim 4.   The biodegradable absorbable polymer of the spring material is poly-L-lactic acid, poly-D, L-lactic acid, a copolymer of L-lactic acid and D, L-lactic acid, a copolymer of lactic acid and glycolic acid, and lactic acid. The implant according to any one of claims 1 to 6, which is any one of a copolymer of p-dioxanone, a copolymer of lactic acid and ethylene glycol, and a copolymer of lactic acid and caprolactone, or a mixture of two or more thereof. A lot.   The implant material body is either a non-porous bioceramic sintered body, a porous bioceramic sintered body, a metal porous body, or a composite porous body of biodegradable absorbent polymer containing bioceramic powder particles. The implant material according to any one of claims 1 to 4.

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