JP3243685B2 - Implant material and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an implant material comprising an X-ray visible surface-treated organic polymer having a property of directly bonding with bone and having a strong (initial) fixation force, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, various implants made of metal, ceramics, organic polymer materials and the like have been known. An implant is a medical device made of one or more biomaterials intended for subcutaneous or partial implantation into the body.
vice).

However, metal implants have an elastic modulus higher than that of living bone by one order of magnitude or more, and thus have a problem such as reduction in strength (asteoporosis) due to stress protection of living bone.
The living body may be damaged by elution of metal ions.
In addition, although ceramic implants have high static strength, they have a problem that they are fragile to impact and are easily chipped or broken.

[0004] Under these circumstances, researches on implants made of organic polymer materials have recently been advanced. For example, as implant materials for joints such as artificial hip joints and artificial knee joints, strength and abrasion resistance (lubricity) have been improved. Excellent bio-inert ultra-high molecular weight polyethylene implant material (the hip head of the artificial hip joint, the tibia plate and patellar of the artificial knee joint)
As an osteosynthesis implant material, osteosynthesis screws, pins, and the like made of polylactic acid that is biodegradable and absorbable without the need for reoperation have come into practical use.

However, as a practical example in which such a polymer is bonded to a living bone by polymer-bone bonding and has durability, various methods for surface-treating the polymer have been studied. But still not seen.

[0006]

The above-mentioned joint implant material made of an organic polymer material does not have direct bonding with living bone, and thus a method of fixing it to living bone with bone cement has been generally used until now. It is used for However, even with this fixation, after years pass, the bone cement peels off at the interface between the bone cement and the living bone, resulting in loosening.
There was a risk that cement and cement fractures would occur and, consequently, the migration of the prosthesis would cause a sink.

Similarly, the osteosynthesis screw and the like made of polylactic acid described above do not have a binding property with living bone, so that it is impossible to maintain the fixing force after the fixation, and it is impossible to avoid the movement after the operation. Some body parts have the problem of "loosening" around the osteosynthesis.

[0008] For this reason, several methods have been devised for the purpose of imparting bonding property with living bone to an implant material made of an organic polymer material. For example, a biomimetic method has been studied in which glass particles mainly composed of calcium oxide and silica are immersed in a simulated body fluid, and an implant material is immersed therein to form a bone-like apatite layer on the surface. The apatite layer formed by is a very thin layer that is hard and covers the surface of the implant material. Therefore, there is a risk of destruction (cracking) under stress due to long-term use, delamination, and detachment. It is not practical.

As another method, a surface grafting method has been devised in which a monomer having a phosphate group is grafted onto the surface of a biologically inert polymer, and then calcium phosphate is formed to induce bone. Due to the submicron order of thickness, bonding with living bone has never been obtained to a desirable degree. That is, there is still no bone bonding implant material that has a strong bonding force with living bone enough to withstand practical use and can maintain it for a long period of time.

[0010] In addition, an implant material consisting of an organic polymer material alone cannot be imaged by X-ray photography because it transmits X-rays. Therefore, the implant material is implanted in a normal state after the operation. There was also a problem that it was not possible to confirm by radiography whether the treatment was proceeding correctly.

An object of the present invention is to provide an implant material which can solve the above-mentioned problems at once, and a method for producing the same.

[0012]

In order to achieve the above object, the implant material of the present invention comprises a body made of a thermoplastic organic polymer material which is inert or biodegradable and absorbs in the body. Is thermally softened, and a bioceramic powder having biocompatibility and bioactivity is embedded by spraying and is exposed on the surface. Desirably, the bioceramics powder is embedded in the surface layer of a depth of 30 μm from the surface of the main body, and the surface is further oxidized.

The thermoplastic organic polymer material is selected from the group consisting of bioinert polyethylene, ultra-high molecular weight polyethylene, polypropylene, polydimethylsiloxane, and polytetrafluoroethylene; Glycolic acid copolymer is preferably used, and bioceramic powders include surface bioactive sintered hydroxyapatite, bioglass, seravital, apatite wollastonite glass ceramic, bioabsorbable Sex (resorbab
le bioactive), unsintered wet hydroxyapatite, tricalcium phosphate, tetracalcium phosphate, octacalcium phosphate, tetracalcium phosphate / dicalcium phosphate dihydride, tetracalcium phosphate / dicalcium phosphate alone or two of these Mixtures of more than one species are preferably used.

The implant material for joints of the present invention has biocompatibility and bioactivity by thermally softening the surface layer of at least the surface layer of the body made of ultra-high molecular weight polyethylene, which is in contact with the living bone. Bioceramic powder is embedded and characterized by being exposed on the surface, the osteosynthesis implant material of the present invention,
At least a surface layer of a body made of polylactic acid or lactic acid-glycolic acid copolymer at a contact portion with a living bone is embedded with bioceramic powder having biocompatibility and bioactivity by thermally softening the surface layer. And exposed on the surface.

Further, according to the production method of the present invention, a body made of a thermoplastic organic polymer material which is bioactive or biodegradable and absorptive and absorbable is heated to soften the surface layer, and a biocompatible bioactive bioactive material is obtained. The ceramic powder is sprayed on the surface of the main body, and the bioceramic powder is embedded in the surface layer of the main body so that the bioceramic powder is exposed on the surface of the main body. The bioceramics powder is heated above the softening temperature of the thermoplastic organic polymer material of the main body, sprayed on the surface of the main body with a compressed air injection device, and embedded in the surface layer from the surface of the main body to a depth of 30 μm. .

In the implant material of the present invention, bioceramic powder having biocompatibility and bioactivity is embedded in the surface layer of the main body and is exposed on the surface. While contacting the bioceramic powder exposed on the surface, bodily fluid also penetrates into the bioceramic powder embedding hole in the surface layer and contacts the powder, and bone tissue is guided around the powder. The anchoring effect (anchorin effect) with the living bone is formed in a state where the bone tissue has entered the surface layer of the body.
g effect). In particular, when the bioceramics powder is embedded in the surface layer up to a depth of 30 μm from the surface, the induction formation of bone tissue and the anchoring effect are improved, the bonding force with the bone is increased, and it does not easily fall off or peel off. If a relatively thick hydroxyapatite (HA) layer is formed and the surface is oxidized, the surface of the polymer is more likely to be wetted by body fluids, and the spread on the surface of the HA layer is improved. The power is significantly improved. Therefore, if the implant material of the present invention is used, in an extreme case, even if it is not unnecessary to fix the bone to the living bone unnecessarily, a strong bond with the living bone may be locally obtained. It is also possible to suppress the loosening of the material for a short or long term.

Further, when the bioceramic powder is embedded in the surface layer of the main body as in the implant material of the present invention, the bioceramic powder has an X-ray contrast ability, so that the implant material can be restored after the operation. It can be confirmed by X-ray imaging whether or not the treatment has progressed correctly in the state of being implanted.

Further, the in vivo implantable joint implant material of the present invention, whose main body is made of ultra-high-molecular-weight polyethylene having excellent strength and abrasion resistance, has the above-mentioned effects and effects under stress caused by long-term use. However, since it is well connected to the living bone, smooth joint movement can be performed for a long period of time.

The biodegradable and absorbable osteosynthesis implant material of the present invention, whose main body is made of polylactic acid or a lactic acid-glycolic acid copolymer which is biodegradable and absorbable, can be decomposed until the osteosynthesis is fused. The strength of the bioceramics embedded in the surface layer portion is small, and the function of the bioceramics powder is combined with the living bone to exert a large fixing force, so that the osteosynthesis can be securely fixed at the initial stage. However, after the osteosynthesis is fused, the degradation proceeds quickly and is absorbed into the living body. No need to do.

According to the production method of the present invention, the implant material of the present invention can be prepared by a simple operation of heating a main body made of a thermoplastic organic polymer material to soften a surface layer portion and spraying a bioceramic powder onto the surface of the main body. Since it is possible to efficiently manufacture bioceramics, the amount and depth of insertion of the bioceramics powder into the surface layer can be selected by selecting the heating conditions for the main body, the size of the bioceramics powder, and the spraying conditions. By adjusting the length, it is possible to easily obtain an implant material having excellent bonding properties with living bone. In particular, if the bioceramic powder is heated above the softening temperature of the thermoplastic organic polymer material of the main body and sprayed on the surface of the main body with a compressed air injection device, the biocera can easily embed the mixed powder,
It can be embedded almost uniformly and efficiently in the surface layer portion up to a depth of 30 μm from the surface of the main body. The powder thus once embedded does not easily come off and fall off because the polymer is slightly fixed when cooled and solidified, because it is strongly fixed.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a front view showing an embodiment of the present invention, showing a screw-shaped osteosynthesis implant material (osteosynthesis screw), and FIG. 2 is a partially enlarged sectional view of the implant material. .

This osteosynthesis screw S is implanted by spraying bioceramic powder 2 having biocompatibility and bioactivity on the surface layer of the main body 1 made of polylactic acid which is biodegradable and absorbable. The structure is such that the powder 2 is exposed on the surface of the main body 1.

The body 1 of the osteosynthesis screw S is formed by melt-molding polylactic acid into a rod shape and then extending the material in the longitudinal direction, or by forging or compressing the polylactic acid into a rod shape. The head 1a and the screw shaft portion 1b are formed by cutting the orientation-molded material, and the hole 1 for fitting a rotating tool such as a hexagon wrench into the head 1a.
c is formed. Polylactic acid has a viscosity average molecular weight of about 300,000 to 600,000 and a crystallinity of 10 to 60
% L- or L-form lactic acid homopolymer (PLL
A, PDLA) are preferred, and such PLLA, P
When DLA is used, an osteosynthesis screw S having high flexural strength and flexural modulus can be obtained.

As a constituent material of the main body 1, in addition to the above-described polylactic acid, a thermoplastic organic polymer material having a biodegradable and absorbable property such as a lactic acid-glycolic acid copolymer is also suitably used.

The bioceramic powder 2 embedded in the surface layer of the main body 1 includes surface-active sintered hydroxyapatite, bioglass, ceravital, apatite wollastonite glass ceramic, bioabsorbable unfired Wet wet hydroxyapatite, tricalcium phosphate, tetracalcium phosphate, octacalcium phosphate, tetracalcium phosphate / dicalcium phosphate dihydride, tetracalcium phosphate / dicalcium phosphate, etc. Select, depending on purpose, alone or 2
Used as a mixture of more than one species. In particular, apatite wollastonite glass ceramics (AW-GC) and the like are very preferably used because of their high ability to induce and form bone tissue.

The bioceramic powder 2 is about 50 μm
It is preferable to use one having the following average particle size. When a bioceramic powder having an average particle diameter of more than 50 μm is used, it is difficult to sufficiently bury the powder in the surface layer of the main body 1 by spraying. In addition, the powder easily falls off, the amount to be embedded (the number of particles to be embedded) is reduced, and the inconvenience that the anchoring effect is reduced is caused. It has been empirically confirmed that a more preferable average particle size is several μm to 30 μm.

The embedding state of the bioceramic powder 2 is as follows.
Ideally, most of the individual particles of the powder 2 are buried in the surface layer of the screw body 1 and part of the particles protrude from the surface of the body 1. Body 1
May be completely buried in the surface layer portion and depressed from the surface. Thus, bio ceramic powder 2
This is because, even if the body is depressed, the bodily fluid can penetrate through the embedding hole and come into contact with the bioceramic powder 2 to induce and form a bone tissue. Alternatively, the surface of the screw body 1 is decomposed in the living body to expose the surface bioceramics, whereby the bone tissue can be induced and combined with the bone. At this time, if the surface of the polymer is oxidized by any method, the wettability with the bodily fluid is good, so that the infiltration of the bodily fluid is improved, and the physiological function of the bioceramic is more effectively expressed.

The embedding depth of the bioceramic powder 2 for obtaining such an embedding state is about several μm to 50 μm from the surface of the screw body 1, preferably several μm to 3 μm.
It is a surface layer of about 0 μm, and if it is deeper than 50 μm, the permeability of body fluid and the ability to induce and form bone tissue decrease. In addition, not only the surface layer portion but also the physical strength of the screw body 1 is reduced, which is not desirable.

The amount of the bioceramics powder 2 to be embedded is preferably about 0.05 to 1.0 mg per unit area (1 cm ² ) of the surface of the screw body 1. 0.
If less than 05 mg, bioceramic powder 2
When the amount exceeds 1.0 mg, the amount of the bioceramic powder 2 that is not sufficiently embedded in the surface layer of the screw body 1 and falls off when the amount exceeds 1.0 mg. Increases and is wasted.

The osteosynthesis screw S of this embodiment is
The bioceramic powder 2 is embedded in the entire surface of the main body 1, and at least a portion (the lower surface of the screw shaft portion 1 b and the head 1 a) that comes into close contact with the living bone at the time of osteosynthesis. What is necessary is that the body 2 is implanted.

The surface of the osteosynthesis screw S is desirably oxidized by, for example, corona discharge treatment. When the surface is oxidized in this way, there is an advantage that the wettability with the body fluid is improved as described above, and the bonding force with the living bone is greatly improved.

The screw S for osteosynthesis having the above structure
Is screwed into the fractured part to perform osteosynthesis, and the bodily fluid comes into contact with the bioceramic powder 2 exposed on the surface of the screw body 1 and penetrates into the embedding hole of the bioceramic powder 2 on the surface layer. Contact with the powder 2
Bone tissue such as hydroxyapatite and collagen is induced around the bone and bonds with the living bone while the bone tissue enters the surface layer of the screw body 1, so that the initial fixation force is greatly improved, and osteosynthesis is achieved. The osteosynthesis portion can be securely fixed without the use screw S loosening. When the initial fixing force is improved in this way, when the osteosynthesis screw S is used on a part of the human body such as a toe, a finger or a joint where the movement is large, the skeletal joint does not loosen with the movement. The effect is remarkable because occurrence of bone and bone resorption (osteolysis) is suppressed as much as possible. Then, although the hydrolysis of the screw body 1 proceeds due to the contact with the body fluid, the strength decrease due to the hydrolysis is small during two to three months until the fracture part is fused, and the fracture part is securely fixed, and the fracture part is fixed. After is fused, hydrolysis proceeds rapidly and is absorbed into the living body. Therefore, there is no need to perform a reoperation for removing from the living body after the osteosynthesis is healed as in the case of the conventional resorbable osteosynthesis implant, unlike a metal osteosynthesis screw.

When an osteosynthesis portion is X-ray photographed after the operation, the outer surface of the screw S is captured in the photographed image because the bioceramic powder 2 on the surface layer has X-ray contrast ability. Therefore, it is also possible to check whether the screw S is implanted in a normal state and the healing is properly proceeding by looking at the photographed image.

Next, a method of manufacturing the osteosynthesis screw S will be described.

First, a screw body 1 made of polylactic acid
To produce The screw body 1 is manufactured by melt-molding polylactic acid into a rod shape and then cutting the material stretched in the longitudinal direction, or by forging and compressing the polylactic acid into a rod shape and orienting and shaping it. I just need.

Next, the screw body 1 is heated to soften the surface layer. The heating temperature of the screw body 1 is 65 to 9
0 ° C. The heating is preferably carried out by heating only the surface portion and keeping the central portion in an unheated state because the shape does not collapse. Therefore, it is desirable to carry out the heating in a furnace at this temperature as short as possible. When heated at a temperature higher than 120 ° C. for a long time, the screw body 1 softens to the inside,
There is a possibility that the orientation of the molecular chains (crystals) is broken and the strength is reduced.

When the surface layer of the screw body 1 softens,
The bioceramic powder 2 is sprayed onto the surface of the screw body 1 while the screw body 1 is being slowly rotated to be embedded in the surface layer. The spraying of the bioceramics powder 2 may be performed using a compressed air injection device (Air Sand Blaster) or the like. The pressure of the compressed air 5~15kg / cm ² or so, preferably set to about 8~10kg / cm ^2, as bioceramics powder 2 is exposed on the surface of the screw body 1, the number of surface μm~50μm about It is important to embed the powder 2 in a surface layer having a depth of preferably several μm to 30 μm. At this time, if the bioceramics powder is previously heated to a temperature equal to or higher than the softening temperature of the polymer of the screw body 1 and injected together with the heated air, it can be efficiently embedded in the surface layer.

When the spraying of the bioceramics powder 2 is completed, the screw body 1 is washed with water to remove the bioceramics powder 2 simply adhering to the surface, thereby obtaining the screw S for osteosynthesis. At this time, the screw body 1
If the surface is oxidized by corona discharge treatment or the like,
There is an advantage that the bondability with the living bone is further improved. This corona discharge treatment may be performed twice before and after embedding the bioceramic powder 2 in the surface layer part, a total of two times. In addition, when the main purpose is not necessarily to improve the connectivity with the living bone, but simply to provide the X-ray contrast function, the corona discharge treatment may not be necessary in some cases.

FIGS. 3 and 4 are a perspective view and a sectional view showing another embodiment of the present invention, showing an implant material for a knee joint.

This knee joint implant material A is obtained by cutting a biologically inactive ultra-high molecular weight polyethylene block by cutting, and forming an artificial knee joint having a stem 10b to be inserted into the tibia on the back surface of the artificial knee joint head plate 10a. The knee joint (main body) 10 is manufactured. And this body 10
Is heated to 120 to 140 ° C. to soften the surface layer, and the back surface of the tibia plate 10a that comes into contact with the living bone that is the proximal end of the tibia,
The bioceramic powder 2 is sprayed on the outer peripheral surface of a leg (stem) 10b inserted into the medulla, and the powder 2 is buried in the surface layer in an exposed state.

As the ultra-high molecular weight polyethylene which is a constituent material of the main body 10, one having a viscosity average molecular weight of 1,000,000 or more is suitably used. Ultra-high molecular weight polyethylene is effective as a constituent material of the body, but polyethylene, polypropylene, and silicone-based polymer (polydimethylsiloxane) are used for joint prostheses of other parts and for prosthesis of bone defects. Bioinert thermoplastic organic polymer materials such as polytetrafluoroethylene may be used.

The air pressure when the bioceramic powder 2 is sprayed by the compressed air injection device is the same as in the case of the osteosynthesis screw described above, and the amount and depth of insertion of the powder 2 are also the same. It is.

When the leg material 10b is inserted into a hole drilled in the head of the patella and fixed, the bone material of the implant material A for an artificial knee joint is converted into a bone tissue by the action of the bioceramic powder 2 in the surface layer. It is guided and formed when it penetrates, and is firmly connected to the patella head. Also, leg 1
Ob is firmly fixed to the tibia in the bone marrow. Therefore, unlike an artificial knee joint in which ultra-high molecular weight polyethylene is not used and is not treated for bonding with any bone currently used, loosening and migration can be prevented for a long period of time. In addition, when the X-ray image is taken, a portion where the bioceramic powder 2 is embedded is photographed, so that it is possible to easily inspect and confirm whether the implant material A is in a normal embedding state.

[0045]

Hereinafter, more specific embodiments of the present invention will be described.

Example 1 A plate obtained by melt-forming poly-L-lactic acid into a plate shape and then cutting the stretched material in the longitudinal direction was heated at 70 ° C. for 3 minutes to soften the surface layer. I let it. Then, a powder of apatite wollastonite glass ceramics (AW-GC) (average particle size: 4 μm) heated to 100 ° C. was applied to the plate surface using a compressed air jetting device having a pressure of 9 kg / cm ² . It was sprayed so that the deepest embedding depth would be 30 μm. The surface is washed with purified water to remove only the adhering powder, and the AW-GC powder is embedded in the surface layer and the poly-L-lactic acid plate exposed on the surface is removed. Obtained. The amount of AW-GC powder embedded in this plate was 0.07 mg / cm ² .

The AW-GC powder spray plate was placed in a simulated body fluid, and a hydroxyapatite film formation test was conducted at 37 ° C. Further, the surface of the same AW-GC powder spray plate was further oxidized by corona discharge treatment, and the same hydroxyapatite film formation test as described above was performed. Then, after 2 weeks, 4 weeks, and 6 weeks, it is taken out, and the surface hydroxyapatite film is scanned with a scanning microscope (SEM).
, And cut the plate to remove SE.
The thickness of the hydroxyapatite film was measured by M, and a peeling test was further performed on the poly-L-lactic acid plate and the hydroxyapatite film using an adhesive tape to examine the adhesion strength. The results are shown in Table 1 below.

[Table 1]

As a result, it was confirmed that the hydroxyapatite film was formed on the surface of the AW-GC powder at an early stage. The peel strength of the formed hydroxyapatite film was significantly improved by corona discharge treatment of the plate surface. And the durability with time was also confirmed.

Example 2 A poly-L-lactic acid was melt-molded into a rod shape, and a screw obtained by cutting a material stretched in the longitudinal direction was heated at 70 ° C. for 3 minutes to form a surface layer. Softened. Then, hydroxyapatite (HA) powder (average particle size 11 μm) heated to 100 ° C. was added to 9
The powder was sprayed onto the screw surface using a compressed air injection device at a pressure of kg / cm ^{2 so} that the deepest embedding depth of the powder was 30 μm. The surface was washed with purified water to remove only the adhering powder, thereby obtaining a poly-L-lactic acid screw in which the HA powder was embedded in the surface layer and exposed on the surface. . HA insertion amount of this screw is 0.11mg
/ Cm ² .

A screw sprayed with the HA powder,
Four screws, a corona-discharge treated screw, a poly-L-lactic acid screw not sprayed with HA powder, and a corona-discharge treated screw, were inserted into the femur of a mongrel dog. The animals were sacrificed at week 4, week 4 and week 6 and the rotational torque required to remove each screw from the bone was measured. The results are shown in Table 2 below.

[Table 2]

As a result, the HA spraying screw exhibited high fixing strength from an early stage, and its removal rotational torque increased with time until after 6 weeks. Thus, it is considered that the screw surface is well bonded to the living bone, early bonding is improved, and loosening or the like is less likely to occur. In addition, a further increase in rotational torque was observed by corona discharge treatment of the surface. Thus, it was confirmed that the bonding property with the living bone was further improved by the corona discharge treatment on the surface.

Example 3 Using an HA powder sprayed poly-L-lactic acid screw obtained in the same manner as in Example 2,
An artificially formed fracture was joined and fixed to the rabbit femur.
X-ray photography after the operation did not show the poly-L-lactic acid screw itself, but the poly-L sprayed with HA powder on the surface.
In the L-lactic acid screw, the entire image of the screw was projected because the HA powder had an X-ray contrast ability.

Example 4 A plate obtained by melt-compression molding ultrahigh molecular weight polyethylene (UHMWPE) having a viscosity average molecular weight of 3.3 million was heated at 130 ° C. for 5 minutes to soften the surface layer. Apatite wollastonite glass ceramics (AW-GC) powder (average particle size: 5 μm) heated to 200 ° C. was applied to the plate surface using a compressed air jetting device at a pressure of 9 kg / cm ² , and the deepest portion of the powder was applied to the plate surface. It was sprayed so that the embedding depth was 30 μm. Then, the surface is washed with purified water to remove only the adhering powder,
A UHMWPE plate in which the AW-GC powder was embedded in the surface layer and exposed on the surface was obtained. AW of this plate
-The insertion amount of the GC powder was 0.3 mg / cm ² .

Next, this plate was placed in a simulated body fluid at 37 ° C., and an attempt was made to form a hydroxyapatite film.
In addition, the surface of the plate produced in the same manner was subjected to corona discharge treatment to try to form a hydroxyapatite film. After 6 weeks from the start of the test, the sample was taken out and the surface was scanned with a scanning microscope (S
EM). The peel strength of the hydroxyapatite film was measured using an adhesive tape. The results are shown in Table 3 below.

[Table 3]

As a result, it was observed that a hydroxyapatite film was formed on the plane of the plate in which the AW-GC powder was embedded in the surface layer of the UHMWPE plate. The adhesive strength at the interface was significantly improved by oxidizing the surface with corona discharge.

Example 5 A UHMWPE plate obtained by the same method as in Example 4 was prepared by embedding AW-GC powder (average particle size: 5 μm) in the surface layer (filling amount: 0.32 mg).
/ Cm ² ) was implanted in the femur of a rabbit, sacrificed 4 weeks and 8 weeks after the operation, and the plate surface was observed. As a comparison, an untreated UHMWPE plate, which was neither corona-treated nor embedded with AW-GC powder, was simultaneously embedded and observed.

As a result, no formation of living bone was observed on the surface of the untreated UHMWPE plate.
-Vigorous formation of living bone was observed on the surface of the UHMWPE plate sprayed with the GC powder. UHMW sprayed with AW-GC powder not subjected to corona discharge treatment
In the PE plate, the HA film partially exfoliated at the interface, but in the UHMWPE plate subjected to corona discharge treatment after spraying AW-GC powder, no interfacial exfoliation was observed and the HA film was firmly fixed to the living bone. It was confirmed that.

As a result, it was confirmed that an implant material made of an organic polymer material could be directly fixed to a living bone via an HA film. The method of this embodiment is, of course, also effective as a surface treatment of UHMWPE such as an artificial hip joint.

[0059]

As is clear from the above description, since the implant material of the present invention is firmly bonded to living bone via the HA membrane, there is little possibility of loosening or migration occurring over a long period of time, and X-ray imaging This has a remarkable effect that the implanted state of the implant material can be easily inspected and confirmed.

The joint implant material of the present invention is well fixed to living bone even under stress caused by long-term use, so that it has an effect that smooth joint operation can be performed, and the osteosynthesis implant material of the present invention can be obtained. By improving the initial fixing strength, the material can be reliably fixed until the fractured portion is fused, and thereafter, it is quickly decomposed and absorbed, so that there is no need to perform reoperation for removing the implant material from the living body.

Further, according to the production method of the present invention, a simple operation of spraying bioceramic powder onto the surface of the main body whose surface layer has been softened by heating and, in some cases, subjecting the surface to an oxidizing treatment, can be used. The implant material can be manufactured efficiently, and the amount and depth of bioceramic powder embedded in the surface layer of the body can be controlled by selecting the heating conditions, powder size, spraying conditions, etc. By adjusting, it is possible to easily obtain an implant material having excellent bonding with living bone.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of the implant material of the present invention.

FIG. 2 is a partially enlarged cross-sectional view of the implant material of the embodiment.

FIG. 3 is a perspective view showing another embodiment of the implant material of the present invention.

FIG. 4 is a sectional view of the implant material of the embodiment.

[Explanation of symbols]

 1,10 body 2 bioceramic powder S osteosynthesis implant material (osteosynthesis screw) A knee implant material

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-339522 (JP, A) JP-A-6-335520 (JP, A) JP-A-2-121652 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) A61L 27/00 A61F 2/30

Claims (6)

(57) [Claims] 1. A bioceramic powder having biocompatibility and bioactivity is thermally softened on a surface layer of a body made of a thermoplastic organic polymer material which is bioactive or biodegradable and absorbable. An implant material which is embedded by spraying and is exposed on the surface. 2. A biocompatible and bioactive bioceramic powder is embedded in a surface layer of a body made of a thermoplastic organic polymer material which is bioactive or biodegradable and absorbable, and is exposed on the surface. An implant material, wherein the surface is oxidized. 3. A bioceramic powder having biocompatibility and bioactivity is sprayed on at least a surface layer of a body made of ultra-high molecular weight polyethylene at a contact portion with a living bone, and the surface layer is thermally softened and implanted by spraying. A joint implant material characterized by being exposed on the surface. 4. A bioceramic powder having biocompatibility and bioactivity by thermally softening the surface layer of at least the surface layer of the body made of polylactic acid or lactic acid-glycolic acid copolymer, which is in contact with living bone. An implant material for osteosynthesis, wherein the body is implanted by spraying and is exposed on the surface. 5. A body made of a thermoplastic organic polymer material which is bioinert or biodegradable and absorbs and softens a surface layer portion, and a bioceramic and bioactive bioceramic powder is applied to the surface of the body. And implanting the bioceramic powder into the surface layer of the main body so that the bioceramic powder is exposed on the surface of the main body. 6. The bioceramics powder is heated to a temperature higher than the softening temperature of the thermoplastic organic polymer material of the main body and sprayed on the surface of the main body by a compressed air jetting device, and 30 μm from the surface of the main body.
The manufacturing method according to claim 5, wherein the material is buried in a surface portion up to a depth of m.