RU2260402C1 - Composition material for osseous tissue replacement - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to composition materials used in making endoprosthesis and in using the composition material for replacement of osseous tissue. The composition material for replacement of osseous tissue comprises a porous matrix made of carbon fiber and carbon material - a filling agent filling pores of matrix partially and wherein the interplanar distance d₀₀₂ in carbon material crystal is 3.58-3.62 Å, and the interplanar distance d₀₀₂ in carbon crystal-a filling agent is 3.42-3.44 Å in the total amount of carbon fiber 20-80%. Invention provides enhancing strength and safety of junction of endoprosthesis material with osseous tissue due to creature of the composition material for replacement of osseous tissue with the elasticity modulus equal with the human and animals elasticity modulus in the range 14-28 hPa.

EFFECT: improved and valuable properties of material.

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Description

The invention relates to the field of composite materials and can be used in medicine for the manufacture of endoprostheses.

Known composite material for bone replacement, including a porous structural element with a pore diameter of not more than 200 microns of carbon fiber and a carbon material is a filler, partially filling the pores so that they are less than 200 microns in diameter. The porous carbon fiber structural member and the carbon filler material form an article that can be used as a prosthetic device to replace human and animal bone tissue (see US Patent No. 5981827, Nov. 2, 1997, for a description of the invention).

This invention is adopted as a prototype.

The disadvantage of the technical solution of the prototype is an unacceptably high modulus of elasticity and its large spread in the production of composite material.

The modulus of elasticity of the bone lies within 14 ... 28 GPa, while the modulus of elasticity of the technical solution of the prototype can reach 30 ... 150 GPa, i.e. exceed the elastic modulus of the bone by an order of magnitude or more. A prosthetic device for replacing bone tissue (endoprosthesis) made of such a material is very \ rigid \ and when installed in a living organism, due to different deformation of the materials of the endoprosthesis and bone, a constant relative movement of the mating surfaces occurs, which leads to a gradual loosening of the endoprosthesis and the absence of conditions for the free growth of bone tissue into the pores and the relief of the material of the endoprosthesis.

At the same time, the conjugation of hard surfaces with healthy bone causes the so-called \ decrease \ healthy bone and inhibits the creation of a homogeneous new bone mass.

The objective of the invention is the creation of a composite material for replacing bone tissue with a modulus of elasticity equal to the modulus of elasticity of the bone tissue of humans and animals and lying within 14 ... 28 GPa. This task is achieved by the fact that in a composite material for bone tissue replacement containing a porous matrix of carbon fiber and a carbon material is a filler partially filling the pores of the matrix, the interplanar distance d _{002 of the} carbon fiber crystal is 3.58 ... 3.62 angstroms, and the interplanar distance d _{002 of the} carbon-filler crystal is 3.42 ... 3.44 angstroms, with a total amount of carbon fiber of 20 ... 80%.

At interplanar distances of the crystal of carbon fiber, carbon filler, and the content of carbon fiber in the range beyond the stated limits, in the composite material for replacing bone tissue, the elastic modulus of bone permissible for humans and animals is exceeded.

The composite material was made as follows: the skeleton of the product is made of carbon fiber, which is close in shape to the replaced area of the bone. In this case, the orientation of the fibers that best ensures the operation of the endoprosthesis under loads is predefined. Then the frame is impregnated with a carbon filler to achieve the required porosity. Impregnation can be carried out by various technological methods, for example, by decomposition of methane at temperatures of 900 ° -1000 ° C. The final refinement of the product is carried out by machining.

The invention is illustrated by the following examples.

Samples of composite material for bone tissue replacement were prepared and tested (elastic modulus determined), where:

- carbon fiber having crystals with d ₀₀₂ , Å

1 - 3,58

2 - 3.60

3 - 3.62

4 - 3.45

5 - 3.68

- carbon filler having crystals with d ₀₀₂ , Å

1 - 3.42

2 - 3.43

3 - 3.44

4 - 3.38

5 - 3.48

- carbon fiber content,%

1-20 7-19 2-55 8-25 3-80 9-40 4-10 10-85 5-15 11-90 6-17

The test results are presented in table 1

Table 1. Experience number Interplanar spacing of a carbon fiber crystal d ₀₀₂ , Å The interplanar distance of the carbon crystal - filler d ₀₀₂ , Å The carbon fiber content,% Modulus of elasticity, GPa Result 1 3.68 3.38 85 55 - 2 3.68 3.38 19 38 - 3 3,58 3.43 twenty 28 + 4 3.62 3.44 80 eighteen + 5 3.45 3.38 17 72 - 6 3.68 3.48 85 40 - 7 3.68 3.48 10 112 - 8 3,58 3.42 55 19 + nine 3.62 3.44 40 26 + 10 3,58 3.44 25 24 + eleven 3.62 3.42 25 21 + 12 3.60 3.44 80 16 + thirteen 3.62 3.42 80 14 + 14 3.45 3.38 85 64 - fifteen 3.45 3.48 fifteen fifty - 16 3.45 3.48 90 92 -

According to the results of the tests shown in table 1, it can be seen that when the interplanar distances of the crystals of carbon fiber and carbon filler and the content of carbon fiber are within the stated limits, the elastic modulus of the composite material is within acceptable limits for humans and animals - examples 3, 4, 8, 9, 10, 11, 12, 13 (the elastic modulus is 14 ... 28 GPa), when going beyond the declared limits it unacceptably increases - examples 1, 2, 5, 6, 7, 14, 15, 16 (elastic modulus is 28 ... 112 GPa).

The positive effect of the use of the invention is to increase the reliability of the connection of the material of the endoprosthesis with bone tissue by creating a composite material for replacing bone tissue with an elastic modulus equal to the elastic modulus of the bone tissue of humans and animals and lying within 14 ... 28 GPa.

Claims (1)

Composite material for bone tissue replacement containing a porous matrix of carbon fiber and a carbon material is a filler partially filling the pores of the material, characterized in that the interplanar distance d _{002 of the} carbon fiber crystal is 3.58 ... 3.62 Å, and the interplanar distance d ₀₀₂ carbon crystal filler - 3.42 ... 3.44 Å, with a total amount of carbon fiber 20 ... 80%.