JP4313005B2 - Implant material - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a bioactive and degradable absorbable implant material used as a vertebral body fixing material (vertebral placement material, vertebral body replacement material).
[0002]
[Prior art]
Conventionally, nerve decompression and lumbar fusion have been performed for lumbar degenerative diseases. Lumbar spine fusion includes posterior fusion, posterior lateral fusion, anterior interbody fusion, etc. Among them, anterior interbody fusion has the advantage of performing spinal canal decompression and anterior strut reconstruction in one step In recent years, it has been actively conducted.
[0003]
Currently, the materials used as the props for anterior interbody fusion include autologous iliac crest and interbody spacers using biomaterials, and the interbody spacers function as a bonding material. Titanium or carbon cages are well known. These cages are usually inserted between the vertebral bodies, filling the transplanted autologous bone inside.
[0004]
[Problems to be solved by the invention]
However, the autologous iliac crest used for the above-mentioned anterior interbody fusion has a problem in that it is fragile as a support and incomplete achievement of spinal column reconstruction due to in vivo absorption over time.
[0005]
In contrast, the above-mentioned biomaterials and interbody spacers made of titanium or carbon have no problem in strength, but titanium cages and carbon cages lack true biocompatibility. There are problems such as fear of expression of harmfulness to surrounding tissues due to destruction over time or corrosion due to remaining as a foreign substance in the body for a long time. There is also a problem that these cages sink into the vertebral body due to the destruction of the osseous endplate caused by reaming, which is caused by the mismatch in mechanical properties between the cage and the living body. In particular, carbon cages are hard but fragile, so they break along the carbon fibers and sometimes generate small pieces, which may cause harm. In addition, autologous bones for transplantation filled in cages made of various materials are generally covered by excision of the iliac bones. However, there are problems in obtaining the amount, and the complexity of the post-extraction surgical procedures (post-treatment of the excised sites). And iliac crushing, cage filling, aseptic treatment, etc.).
[0006]
An object of the present invention is to provide an in vivo active and fully absorbable implant material that can solve these problems.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, an implant material according to the present invention has a cavity that communicates with the outside, and the inside of the mother body made of a biodegradable absorbable polymer containing a bioactive bioceramic powder is continuous inside. Bioactive bioceramics powder in a porous matrix of biodegradable absorbent polymer with pores Equally within the range of 60 to 90% by weight The porous body is filled and the porous body is partially exposed.
[0008]
When such an implant material is inserted between vertebral bodies, for example, as various interbody spacers, the mother body, which has sufficient strength and plays the same role as the cortical bone of a living body, comes into contact with body fluids and gradually undergoes hydrolysis from the surface. To do. The porous body, which plays the same role as cancellous bone, has a body fluid penetrating into the interior through continuous pores from the exposed part and hydrolysis proceeds rapidly, and osteoblasts are porous due to the osteoconductivity of the bioceramic powder. The bone tissue penetrates into the inside of the body, and the bone tissue is conductively formed. Therefore, the upper and lower vertebral bodies are fused and fixed by this bone tissue. The mother body undergoes hydrolysis later than the porous body, maintains the strength as a spacer at least during the period until bone union, and eventually disappears by replacing with bone tissue.
[0009]
As described above, the implant material of the present invention is decomposed and absorbed by both the mother body and the porous body to replace the bone tissue and does not remain in the living body as a foreign body. Therefore, there is a concern about the conventional titanium or carbon cage. Such a long-term presence in a living body can eliminate the fear of expression of harm and the problem of subsidence into the vertebral body caused by a mismatch in mechanical properties with the living body. Moreover, because the porous body performs histological action similar to that of living bone and replaces bone tissue, it is not necessary to extract the iliac bone as a transplanted autologous bone for filling into the cage as in the past. Thus, the problem of insufficient acquisition of autologous bone for transplantation and the problem of complicated processing at the time of surgery after extraction can be eliminated.
[0010]
In the implant material of the present invention, it may be desirable not only to fill the porous body in the cavity of the mother body but also to provide the porous body in a plate shape so as to overlap the upper and lower sides of the mother body. In this way, when the implant material of the present invention is inserted between vertebral bodies, for example, the upper and lower porous bodies are compressed by the clamping pressure of the vertebral bodies and are in close contact with the vertebral bodies without any gaps. Since cells can easily enter the porous body, bone tissue is conductively formed on the surface layer of the porous body at an early stage, and there is an advantage that the implant material is directly bonded to the vertebral body and stably fixed.
[0011]
In the implant material of the present invention, the porosity of the porous body is 50 to 90%, the continuous pores account for 50 to 90% of the total pores, and the pore diameter of the continuous pores is about 100 to about 400 μm. Is desirable in the sense that it is directly coupled to the vertebral body.
[0012]
The implant material of the present invention desirably has a content of bioceramic powder in the porous body of 60 to 90% by weight. When such a content is obtained, the bone conductivity is lower than that of the porous body having a lower content. Is sufficiently exerted, and the porous body is replaced with bone tissue within a relatively short period of time. Further, the foreign body reaction around the strip caused by hydrolysis of the resorbable polymer having no osteoconductivity is further avoided.
[0013]
Moreover, in the implant material of the present invention, it is desirable to form the mother body in a rectangular parallelepiped shape having hollow entrances on four sides, top, bottom, left, and right, and in this way, installation stability when the implant material is inserted between vertebral bodies is desirable. And the body fluid also easily penetrates into the porous body in the cavity from the entrances of the four surfaces. When the upper surface of the mother is inclined forward and downward and the lower surface is inclined forward and upward, the implant material is suitable for correcting the lumbar vertebra to the front bay posture. Further, when a plurality of cavities are formed in the mother body and a communication hole is formed in the wall portion between the cavities, the pressure resistance strength of the implant material is improved by the wall portion, and the bone tissue replaced with the porous body in the cavity. Can be connected through the communication hole. In addition, by providing fixing protrusions on both the upper and lower surfaces of the mother body, the protrusions can be fixed so that the protrusions do not bite into the upper and lower vertebral bodies and the implant material does not shift or come out. ) Implant material.
[0014]
The shape of the matrix is not limited to the above-mentioned rectangular parallelepiped shape. For example, it is formed into an annular shape having a cavity inside, or a cylindrical shape having a cavity inside and a plurality of cavity inlets on the outer peripheral surface. It can be formed into various shapes suitable for the use site such as the spine, cervical vertebra, lumbar vertebra and the like. Moreover, it is desirable that the content of the bioceramic powder in the mother body is 10 to 60% by weight. With such a content, sufficient osteoconductivity can be exhibited without weakening the mother body.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.
[0016]
1 is a perspective view of an implant material according to an embodiment of the present invention, FIG. 2 is a perspective view of a parent body of the implant material, FIG. 3 is a longitudinal sectional view of the implant material, and FIG. 4 is a longitudinal section of the parent body of the implant material. FIG. 5 and FIG. 6 are a side view and a rear view showing the implant material inserted between the vertebral bodies.
[0017]
5 and 6, the implant material 10 is inserted between the vertebral bodies B and B of the spine as intervertebral body spacers. As shown in FIGS. And a porous body 2a filled in the cavity 1a of the base body 1 and a porous body 2b provided in a plate shape so as to overlap the top and bottom of the base body 1. As will be described later, the porous body 2b is provided in order to eliminate the gap between the mother body 1 and the vertebral bodies B and B and enable early coupling, and can be omitted.
[0018]
The matrix 1 of the implant material 10 is a dense and strong matrix made of a biodegradable absorbable polymer containing a bioactive bioceramic powder, and has a rectangular parallelepiped shape as shown in FIGS. Is formed. The base body 1 is formed so that two longitudinal through-hole cavities 1a leading to the outside and two lateral through-hole cavities 1a intersect each other, and an inlet 1b of these cavities 1a is formed. Two openings are provided on each of the upper, lower, left and right surfaces of the mother body 1. The inlets 1b of these cavities 1a serve as entrances for body fluids and the like, and the porous bodies 2a filled in the cavities 1a are partially exposed from the respective inlets 1b. The inlet 1b of the cavity 1a can also be formed on the front surface or the rear surface of the mother body 1. In this case, the rear surface inlet can be formed in a screw hole shape so that the tip of the insertion jig can be screwed. It is good to make it.
[0019]
In this implant material 10, the four circumferences of the front surface 1c of the mother body 1 are chamfered so that the insertion between the vertebral bodies B and B is easy. Then, several (six in the figure) fixations are performed on the upper and lower surfaces 1d and 1e of the mother body 1 so that the implant material 10 inserted between the vertebral bodies B and B is not displaced or pulled out. The protrusions 1 f are provided, and the tip portions of the protrusions 1 f protrude from the porous bodies 2 b on the upper and lower surfaces of the base 1. As shown in FIG. 2, the projection 1 f has a pin 1 h (1 f) in which concave holes 1 g are formed on the upper and lower surfaces of the mother body 1 and the tip made of the same biodegradable absorbent polymer as the mother body 1 is pointed in a conical shape. It is planted in the concave hole 1g. Instead of the pin 1h, a projecting piece with a sharp tip may be planted. Further, the protrusion 1 f may be formed integrally with the base body 1.
[0020]
As shown in FIGS. 3 and 4, a communication hole 1j is formed in the wall portion 1i between the two cavities 1a and 1a in the vertical direction of the base 1, and is filled in the cavity as will be described later. Bone tissue conductively formed in the porous bodies 2a, 2a can be connected through the communication hole 1j. The wall portion 1 i serves to increase the pressure resistance strength of the mother body 1.
[0021]
The size of the mother body 1 is about 18 to 30 mm in the front-rear dimension, about 6 to 24 mm in the upper and lower height dimension, and the left and right width dimension. A body suitable for the size of the body B, B and the intervertebral dimension can be selected and inserted.
[0022]
The mother body 1 of the embodiment shown in FIGS. 1 to 4 has the longitudinal and lateral cavities 1a formed in the shape of through holes having an oval cross section, but various cross sectional shapes such as a quadrangle, a circle, and an ellipse. You may form in the through-hole shape which has. Alternatively, the entire inside of the mother body 1 may be formed as a hollow chamber-like cavity, and the inlets of the cavity may be formed on the upper, lower, left, and right surfaces of the mother body 1 so that the cavity and the outside communicate with each other.
[0023]
Note that the cavity 1a penetrating in the lateral direction of the mother body 1 can be omitted. If there is a cavity 1a penetrating in the longitudinal direction, the bone tissue from the upper and lower vertebral bodies B and B is inserted into the porous body 2a inserted therein. Is formed by conduction, fused and fixed. Further, the left and right inlets 1b of the mother body 1 can be omitted.
[0024]
The matrix 1 is composed of a biodegradable absorbent polymer containing biolamix powder as described above, and the biodegradable absorbent polymer as a raw material has been confirmed to be safe in vivo. Crystalline poly-L-lactic acid and polyglycolic acid are preferably used, and in particular, a high-strength matrix using poly-L-lactic acid having a viscosity average molecular weight of 150,000 or more, preferably about 200,000 to 600,000 1 is preferred. Such a matrix 1 is manufactured by a method such as injection molding of a biodegradable absorbable polymer or cutting a molded block of the biodegradable absorbable polymer. Is a block in which polymer molecules and crystals are oriented by means of compression molding, forging, etc., and the matrix 1 obtained by cutting this is dense and the polymer molecules and crystals are three-dimensionally oriented to increase the strength. It is extremely suitable because it improves further. In addition, a block formed by stretching as a molding block can also be used suitably, and it is also preferable to increase the strength by cutting so that the stretching direction (orientation direction) is the longitudinal direction.
[0025]
The bioceramic powder to be contained in the biodegradable absorbable polymer of the matrix 1 is bioactive, has good osteoconductivity and good biocompatibility, and has not been calcined, unfired hydroxyapatite, di Powders such as calcium phosphate, tricalcium phosphate, tetracalcium phosphate, octacalcium phosphate, calcite, serabital, diopsite, smallpox are used. The content of the bioceramic powder is preferably in the range of 10 to 60% by weight, and if it is less than 10% by weight, the formation of bone conduction by the bioceramics powder becomes insufficient, and if it exceeds 60% by weight, the matrix 1 becomes brittle. Cause inconvenience.
[0026]
On the other hand, both of the porous bodies 2a and 2b have continuous pores inside. Including bioactive bioceramics powder in porous matrix of biodegradable absorbent polymer In other words, a part of the bioceramic powder is exposed on the surface of the porous body and the inner surface of the continuous pores.
[0027]
The porous body 2a is filled in the cavity 1a of the base body 1 by one of the following two methods.
[0028]
In the first method, first, a biodegradable polymer is dissolved in a volatile solvent and a bioceramic powder is mixed to prepare a suspension. The suspension is made into a fiber by means such as spraying. A fiber assembly in which fibers are intertwined is formed. Next, the fiber assembly is packed into the cavity 1a from the inlet 1b of the cavity of the mother body 1 and heated to a temperature at which the fibers can be fused, so that the fibers are partially fused to form a porous fiber. Let it be a fused assembly. Then, this fiber fusion aggregate is immersed in a volatile solvent together with the base material 1 to shrink and fuse the fibers, thereby substantially eliminating the fibrous form and forming a matrix so that the inter-fiber voids are rounded. The porous body 2a having continuous pores having a shape is filled with a change in shape.
[0029]
In the second method, the above-mentioned fiber assembly is heated and pressurized to form a porous fiber fusion aggregate having a shape (columnar shape having an oval cross section) matching the cavity 1a. The body is immersed in a volatile solvent to change its shape to the porous body 2a, and then inserted into the cavity 1a of the base body 1 for filling.
[0030]
On the other hand, the porous body 2b is formed by heating and pressurizing the above fiber assembly to form a porous plate-like fiber fusion aggregate, and immersing this plate-like fiber fusion aggregate in a volatile solvent. The substantially fibrous form disappears and the form is changed to a plate-like porous body having continuous pores. The porous body 2b is formed with a hole through which the protrusion 1f of the mother body 1 is passed, is overlaid on the upper and lower surfaces 1d and 1e of the mother body 1, and is fixed by means such as heat welding. The thickness of the porous body 2b is preferably about 0.5 to 3 mm. If the thickness is less than 0.5 mm, it is difficult to absorb the irregularities on the surface of the vertebral body B due to compression deformation. On the other hand, if it is thicker than 3 mm, the time required for decomposition and resorption and replacement with bone tissue becomes longer.
[0031]
Since these porous bodies 2a and 2b are not required to have the strength as the base 1, they need to be decomposed relatively quickly and replaced with bone tissue formed by conduction with bioceramic powder. The biodegradable and absorbable polymer used as the raw material is safe, relatively quick to decompose, not very brittle, 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 caprolactone copolymer, lactic acid and ethylene glycol copolymer, lactic acid and para-dioxanone copolymer, etc. are suitable. These may be used alone or in admixture of two or more. Among these polymers, those having a viscosity average molecular weight of about 50,000 to 1,000,000 are preferably used in consideration of the ease of forming a fiber aggregate by fiberization and the period of decomposition and absorption in vivo.
[0032]
In addition, as the bioceramic powder contained in the porous bodies 2a and 2b, all of the bioceramic powder contained in the matrix 1 described above is used. Substituted bioabsorbable bioceramic powders are preferred. In particular, uncalcined and uncalcined hydroxyapatite, tricalcium phosphate, and octacalcium phosphate have extremely high bioactivity, excellent osteoconductivity, and harm. It is optimal because it has low properties and is absorbed by the living body in a short period of time. Those bioceramic powders having a particle size of 10 μm or less are preferably used, and those having a particle size of about 0.2 to 5 μm are fiberized by means such as spraying to form a fiber aggregate. In this case, since the fiber is short and not cut, it is very preferably used.
[0033]
The content of the bioceramic powder in the porous bodies 2a and 2b is preferably 60 to 90% by weight, and if it exceeds 90% by weight, fibers are formed when forming fiber aggregates by means of spraying or the like. On the other hand, if it is less than 60% by weight, the formation of conduction in the bone tissue is delayed, and it takes time for the porous bodies 2a and 2b to replace the bone tissue. The more preferable content rate of bioceramics powder is 60 to 80 weight%.
[0034]
The above porous bodies 2a and 2b have a porosity of 50 to 90% (preferably 60 to 80%) in consideration of physical strength, invasion and stabilization of osteoblasts, and the continuous pores are the entire pores. It is desirable that the pore diameter of the continuous pores is about 100 to about 400 μm (preferably 150 to 350 μm). When the porosity exceeds 90% and the pore diameter is larger than 400 μm, the physical strength of the porous bodies 2a and 2b is lowered and becomes brittle. On the other hand, when the porosity is less than 60%, the continuous pores are less than 50% of the total pores, and the pore diameter is smaller than 100 μm, the infiltration of body fluids and osteoblasts is reduced, and the porous bodies 2a and 2b are hydrolyzed. The growth of the bone tissue becomes slow, and the time required for the porous bodies 2a and 2b to replace the bone cells becomes long.
[0035]
The porous bodies 2a and 2b preferably contain appropriate amounts of various bone forming factors, growth factors, drugs and the like. BMP as the main osteogenic factor, monokines and lymphokines such as IL-1, TNF-α, TNF-β, IFN-γ, colony stimulating factor, or TGF-α as the main growth factors , TGF-β, IGF-1, PDGF, FGF and so-called growth differentiation factors. In addition, as the drug, drugs related to bone growth (such as vitamin D, prostaglandins, or anti-cancer drugs), antibacterial agents, and the like can be arbitrarily selected. When the growth factors as described above are contained in the porous bodies 2a and 2b, bone formation is remarkably promoted inside the porous bodies 2a and 2b, and the porous bodies 2a and 2b are replaced with bone tissue at an early stage. , B comes to heal. Then, when the drug as described above is impregnated, the drug is absorbed by the vertebral bodies B and B and the drug effect is sufficiently exhibited.
[0036]
Further, the surface of the porous body 2b and the exposed surface of the porous body 2a may be subjected to oxidation treatment such as corona discharge, plasma treatment, hydrogen peroxide treatment, etc., and when such oxidation treatment is carried out, the surface biodegradable absorption Since the wettability of the conductive polymer is improved and the osteoblasts penetrate and grow more effectively inside the porous body 2b, there is an advantage that the implant material 10 is bonded to the vertebral bodies B and B at an early stage. .
[0037]
The implant material 10 as described above is inserted into a pair of left and right vertebral bodies B, B using an insertion jig as shown in FIGS. It will be corrected. When the implant material 10 is inserted in this way, the porous bodies 2b, 2b on both the upper and lower surfaces of the mother body 1 are compressed by the clamping force of the vertebral bodies B, B and are in close contact with the vertebral bodies B, B without any gaps. The protrusions 1f on both sides are fixed so that the implant material 10 does not slip out or slip out into the cancellous bones of the vertebral bodies B and B, and is stable in combination with the matrix 1 having a rectangular parallelepiped shape. Well installed.
[0038]
When the implant material 10 is inserted and installed between the vertebral bodies B and B as described above, the mother body 1 comes into contact with the body fluid and hydrolysis proceeds gradually from the surface. The porous bodies 2a and 2b are rapidly hydrolyzed by the body fluid penetrating the inside through continuous pores, and osteoblasts enter the porous bodies 2a and 2b due to the osteoconductivity of the bioceramic powder. Since the bone tissue is conductively formed, the porous bodies 2a and 2b replace the bone tissue within a relatively short period of time. Therefore, the upper and lower vertebral bodies B and B are fused and fixed by the replaced bone tissue. On the other hand, the mother body 1 has a high compressive strength from the beginning in the same manner as the carbon cage, and maintains the strength even after the porous bodies 2a and 2b are replaced with bone, so that the implant material 10 is completely vertebral body. It plays a great role in being fused and mechanically fixed with B. After several years (about 5 years), the replacement with bone tissue is completed. At this point, solid fusion with living bone is completely obtained.
[0039]
The conduction formation of the bone tissue is achieved by the fact that the porous body 2b on both the upper and lower surfaces of the mother body 1 is compressed and is in close contact with the vertebral bodies B and B without gaps, and the bioceramic powder having bone conduction ability is applied to the porous bodies 2a and 2b. 60 to 90% by weight, the porosity of the porous bodies 2a and 2b is 50 to 90%, the continuous pores account for 50 to 90% of the total pores, and the pore size of the continuous pores is about 100 to about 400 μm. Therefore, the osteoblast is easily and reliably invaded, and the implant material 10 is directly coupled to the upper and lower vertebral bodies B and B at the initial stage when the bone tissue is conductively formed on the surface layer of the porous body 2b. Fixed.
[0040]
FIG. 7 is a perspective view of an implant material according to still another embodiment of the present invention, and FIG. 8 is a perspective view of a parent body of the implant material.
[0041]
This implant material 11 is formed by penetrating two vertical cavities 1a, 1a (square hole cavities) having a rectangular cross-sectional shape through a rectangular parallelepiped base 1 on both upper and lower surfaces of the base 1. Two rectangular cavity inlets 1b are formed on each side, and two oval-shaped cavity inlets 1b are formed on the left and right side surfaces of the mother body 1, respectively. A communication hole 1j is formed in the wall 1i between the two cavities 1a and 1a.
[0042]
In addition, two protrusions 1f for fixing are formed on the front and rear edges of the upper and lower surfaces 1d and 1e of the base body 1 over the entire length in the width direction, and an intermediate portion (wall) between the upper and lower surfaces 1d and 1e. Also on the upper and lower ends of the part 1i, one fixing protrusion 1f is formed over the entire length in the width direction. These protrusions 1f are formed integrally with the mother body 1 by cutting or the like, and the tips of the protrusions 1f are inclined so as not to prevent the insertion of the implant material 10 between the vertebral bodies B and B. Yes. In addition, you may form the protrusion 1f short in the shape of a protrusion.
[0043]
The cavity 1a of the base 1 is filled with the porous body 2a described above and is partially exposed from the entrance 1b of the cavity. The body 2b is provided in an overlapping manner.
[0044]
Such an implant material 11 is also inserted between the vertebral bodies as an intervertebral body spacer in the same manner as the implant material 10 described above, and exhibits the same effects.
[0045]
FIG. 9 is a side view of an implant material according to still another embodiment of the present invention.
[0046]
This implant material 12 is different from the aforementioned implant material 10 in that the upper surface 1d of the mother body 1 is inclined forward and downward, and the lower surface 1e is inclined upward and downward. Since other configurations are the same as those of the implant material 10, the same members are denoted by the same reference numerals in FIG.
[0047]
Such an implant material 12 is also inserted between vertebral bodies as an intervertebral body spacer, and has the same effect as the implant material 10 described above, but in addition, both the upper and lower surfaces so that the mother body 1 is tapered. Since 1d and 1e are inclined, it is suitable for correcting the lumbar vertebra to the front bay posture.
[0048]
FIG. 10 is a perspective view of an implant material according to still another embodiment of the present invention.
[0049]
In this implant material 13, the base 1 is formed in a cylindrical shape having a cavity 1a (a cavity having a circular cross section) on the inside, and one circular cavity inlet 1b is formed on each end face of the outer peripheral surface. A large number of oblong hollow openings 1b are arranged in a staggered pattern. The cavity 1a of the base body 1 is filled with the porous body 2a described above, and the porous body 2a is partially exposed from the respective inlets 1b formed on both end faces and the outer peripheral surface of the base body 1.
[0050]
Such an implant material 13 is inserted between the vertebral bodies in a vertically oriented posture as shown in the figure, and like the above-described implant material 10, the mother body 1 and the porous body 2a are finally replaced with bone tissue, The vertebral bodies are fused and fixed.
[0051]
FIG. 11 is a perspective view of an implant material according to still another embodiment of the present invention.
[0052]
This implant material 14 has a male screw 1k formed on the outer peripheral surface of a cylindrical body 1 having a cavity 1a (a cavity having a circular cross section) on the inside. One end of a circular cavity 1b is formed on both end faces of the mother body 1 and two large oval inlets 1b are arranged on the outer peripheral surface. The aforementioned porous body 2 filled in the cavity 1a is partially exposed from each of the inlets 1b.
[0053]
Such an implant material 14 is installed so that the porous body 2 exposed from the entrance 1b formed above and below the outer peripheral surface substantially contacts the end plates of the upper and lower vertebral bodies by screwing between the upper and lower vertebral bodies. In the same manner as the above-described implant material, the mother body 1 and the porous body 2a finally replace the bone tissue to fuse and fix the upper and lower vertebral bodies. The implant material 14 is desirably used in combination with a vertebral body fixing jig to improve initial installation stability.
[0054]
FIG. 12 is a perspective view of an implant material according to still another embodiment of the present invention.
[0055]
The implant material 15 is formed in an annular shape in which the base 1 has a portion 1n having a small curvature, and the porous body 2a is filled in the cavity 1a inside thereof, and the inlets 1b above and below the cavity are filled. The upper and lower surfaces of the porous body 2a are exposed. Although the cavity entrance is not formed on the outer peripheral surface of the annular body 1, a plurality of cavity entrances may be formed in some cases. Further, the fixing protrusions described above may be formed on the upper and lower surfaces of the annular body 1.
[0056]
Such an implant material 15 is inserted between the vertebral bodies with the small curvature portion 1n of the mother body 1 as the rear side, and the mother body 1 and the porous body 2a finally replace bone tissue in the same manner as the aforementioned implant material. To unite and fix the upper and lower vertebral bodies.
[0057]
As mentioned above, although the implant material of the present invention has been described with reference to the main embodiment, the implant material of the present invention is not limited to the interbody spacer, and the shape of the mother body is appropriately set as an implant material for bone joint fixation. It is changed and used for the bone joint of each part.
[0058]
【The invention's effect】
In the implant material of the present invention, the porous body is rapidly decomposed and absorbed and replaced with bone tissue in a relatively short period of time, and the mother body that is slow to total decomposition and absorption is finally decomposed and absorbed and replaced with bone tissue. Therefore, it is possible to surely eliminate the fear of expression of harm due to remaining in the body as a foreign body like conventional titanium or carbon implant materials, and bones arising from mismatch of mechanical properties with bone The problem of subsidence can be solved reliably. The porous body is replaced with bone tissue to play the role of substitute bone graft, and to fuse and fix vertebral bodies and bone joints, the iliac bone etc. can be removed as conventional bone for transplantation. Is eliminated, and the problem of acquiring the autologous bone for transplantation and the trouble of the complicated processing at the time of operation after the extraction can be eliminated.
[Brief description of the drawings]
FIG. 1 is a perspective view of an implant material according to an embodiment of the present invention.
FIG. 2 is a perspective view of a parent body of the implant material.
FIG. 3 is a longitudinal sectional view of the implant material.
FIG. 4 is a longitudinal sectional view of the matrix of the implant material.
FIG. 5 is a side view showing the same implant material inserted between vertebral bodies.
FIG. 6 is a rear view showing the same implant material inserted between vertebral bodies.
FIG. 7 is a perspective view of an implant material according to another embodiment of the present invention.
FIG. 8 is a perspective view of the matrix of the implant material.
FIG. 9 is a side view of an implant material according to yet another embodiment of the present invention.
FIG. 10 is a perspective view of an implant material according to yet another embodiment of the present invention.
FIG. 11 is a perspective view of an implant material according to yet another embodiment of the present invention.
FIG. 12 is a perspective view of an implant material according to yet another embodiment of the present invention.
[Explanation of symbols]
1 Mother
1a cavity
1b Cavity entrance
1d Upper surface of mother body
1e Underside of the mother body
1f Protrusion for fixing
1i wall
1j communication hole
2a, 2b porous body
10, 11, 12, 13, 14, 15 Implant material

Claims (10)

In the porous matrix of the biodegradable absorbable polymer having continuous pores in the cavity of the matrix made of the biodegradable absorbable polymer having the cavity leading to the outside and containing the bioactive bioceramic powder An implant material comprising a porous body uniformly containing a bioactive bioceramic powder within a content range of 60 to 90% by weight , wherein the porous body is partially exposed.   The implant material according to claim 1, wherein the porous body is provided in a plate shape so as to overlap the top and bottom of the matrix.   The implant according to claim 1 or 2, wherein the porosity of the porous body is 50 to 90%, the continuous pores occupy 50 to 90% of the total pores, and the pore diameter of the continuous pores is about 100 to about 400 µm. material. The implant material according to any one of claims 1 to 3 , wherein a content of the bioceramic powder in the matrix is 10 to 60% by weight. The implant material according to any one of claims 1 to 4 , wherein the mother body is formed in a rectangular parallelepiped shape having hollow entrances on four surfaces, top, bottom, left, and right. The implant material according to claim 5 , wherein the upper surface of the mother body is inclined forward and downward and the lower surface is inclined upward and forward. The implant material according to claim 5 or 6 , wherein a plurality of cavities are formed in the mother body, and communication holes are formed in a wall portion between the cavities. The implant material according to any one of claims 5 to 7 , wherein fixing protrusions are provided on both upper and lower surfaces of the mother body. The implant material according to any one of claims 1 to 4 , wherein the matrix is formed in an annular shape having a cavity inside. The implant material according to any one of claims 1, 3, and 4, wherein the parent body is formed in a cylindrical shape having a cavity on the inner side and a plurality of cavity inlets provided on the outer peripheral surface.

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