JPH0231749A - Filler for bone depleted part and osteoporosis part - Google Patents

Abstract

PURPOSE:To easily fill the affected part by making the cross-sectional shape of a columnar or polyhedral filler containing a calcium phosphate compound substantially same and setting the ratio of the length of said filler to the cross- sectional diameter thereof to a specific range. CONSTITUTION:The cross-sectional shape of a columnar or polyhedral filler containing a calcium phosphate compound is made substantially same and the ratio of the length of said filler to the cross-sectional diameter thereof is set to a range of 0.1-10. The usable calcium phosphate compound pref. contains hydroxyapatite and, especially, hydroxyapatite baked at 500 deg.C or higher is bonded to a bone depleted part over a long period of time to develop bone forming action because the new bone forming speed thereof is high and the solubility thereof is low. The usable cross-sectional diameter of the filler is desirably within a range of 0.2-10mm and, when said diameter exceeds 10mm, the formation of the new bone around the filler becomes slow and, when the diameter is below 0.2mm, the filler is allowed to flow by blood and not bonded to a filling place and sufficient bone forming effect is not expected.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a filling material for bone defects and bone fragments, and more particularly to a filling material for bone defects and bone fragments containing a calcium phosphate compound.

<Prior Art and Its Disadvantages> Osteoporosis is a group of diseases in which bone mass decreases due to various causes. When humans reach the age of approximately 20, bone growth is complete.
Its length and width reach its maximum, and the amount reaches its maximum between the ages of 20 and 30. but.

As people reach middle age and old age, the size of their bones does not change much even in healthy people, but their bones become thinner and their bone mass decreases. especially,
Some women rapidly lose bone mass after menopause, and some men and women rapidly lose bone mass over the age of 65. In addition, bone mass may decrease due to endocrine diseases, gastrointestinal, liver, and kidney diseases, or induced by the administration of drugs such as glucocorticoids, resulting in osteoporosis. decreases, making fractures more likely. for example,
Typical examples of such fractures include vertebral compression fractures, femoral neck fractures, and distal radius fractures.

Traditionally, the only treatment for osteoporosis was drug therapy using female hormones, active vitamin D, calcitonin, etc. Drug therapy involves reducing the vertebral bodies of the vertebrae that have become wedge-shaped or compressed due to compression fractures. On the other hand, calcium phosphate compounds have osteogenic ability and are useful as fillers for filling bone defects and bone voids. It has been known.

However, when applied to the treatment of osteoporosis, it is necessary to fill and inject a predetermined amount of calcium phosphate compound into a specific area of bone loss, and the filling process is particularly difficult when the surgical site is deep.

To solve this problem, it is desirable to fill the area through a filling syringe, but the known filling materials for bone defects and bone voids made of calcium phosphate compounds have fluidity problems, so it is not possible to fill them through a filling syringe. difficult6
In addition, when used for the treatment of osteoporosis, there is also the problem that the filler remains attached to the bone-depleted area for a long period of time, and an increase in bone mass must be expected.

Therefore, for example, in Japanese Patent Application Laid-Open No. 62-268562, particles made of a calcium phosphate compound,
A filler for treating skeletal beard disease has been proposed that includes calcium phosphate compound particles whose major axis ratio is in the range of 1:1 to 1:5 and whose angle of repose is in the range of 10° to 45°. however.

In this prior art invention, although the problem of fluidity of calcium phosphate compound particles was somewhat solved, there was a problem that filling could not be carried out smoothly when the affected area was deep, and the shape of the particles was unspecified. Therefore, there are cases where filling becomes impossible when extruding in a certain direction with a filling syringe. Furthermore, the actual situation is that the osteogenic ability when combined with other substances 1, such as bone morphogenetic factors and fibrin, is not sufficient.

<Problems to be Solved by the Invention> The main purpose of the present invention is to provide bone defects and osteoporosis that have good fluidity and can be poured directly into the affected area, or can be filled into the affected area extremely easily using a filling device. The purpose of the present invention is to provide a granular filler.

Another object of the present invention is to provide a filling material for bone defects and skeletal whiskers that has good fluidity and can properly fill deep parts of the body when filled with an injection device.

Another object of the present invention is to provide a filling material for bone defects and bone debris that has good fluidity and can make the incisions extremely small when filled with an injection device.

Still another object of the present invention is that despite having good fluidity, it remains attached to the filling area for a long time after filling.
An object of the present invention is to provide a filling material for bone defects and coarse bones that can increase bone mass.

<Means for Solving the Problems> According to the present invention, there is provided a cylindrical or polygonal cylindrical filling material containing a calcium phosphate compound, in which the cross-sectional shape of the filling material is substantially the same, and the ratio of length to cross-sectional diameter is is 0.1~
A filling material for bone defects and osteoporosis is provided, which is characterized in that the amount is in the range of 1o.

The present invention will be explained in more detail below.

Calcium phosphate compounds that can be used in the present invention include tricalcium phosphate, hydroxyapatite, tetracalcium phosphate, oxyapatite, calcium pyrophosphate,
Examples include fluoroapatite and mixtures thereof, and particularly preferred are one or two of the group consisting of tricalcium phosphate, hydroxyapatite, fluoroapatite, and tetracalcium phosphate, which have a high rate of new bone formation. It is desirable to select one from the above. Among them, it is preferable to contain hydroxyapatite, especially at 500°C.
As mentioned above, hydroxyapatite calcined more preferably at 700° C. or higher has the fastest new bone formation rate and low solubility, so it is particularly desirable because it adheres to bone loss areas for a long period of time and produces a tube-forming effect. The upper limit temperature of the heat treatment is not particularly limited, but since hydroxyapatite starts to decompose, it should be 5 decomposition temperatures or lower.

In addition, the calcium phosphate compound that can be used in the present invention may be artificially synthesized by a known manufacturing method such as a wet method, a dry method, or a hydrothermal method, or it may be a natural product obtained from bones etc. You can.

It is essential that the filling material used in the present invention be a cylinder or a polygonal cylinder, but the cross-sectional shape of the cylinder or polygonal cylinder and the cylindrical shape of the injection device should match as long as it does not interfere with filling. For example, there is no particular need for the side portions to be sharp. Whether the shape of the filling material is cylindrical or polygonal is preferably selected appropriately depending on whether the holder of the injection device used and the cross-sectional shape of the injection cylinder are cylindrical or polygonal. .

The cross-sectional diameter of the filler that can be used in the present invention is 0.2 to 10
IIIl, preferably in the range of 0.2 to 5 m. If the cross-sectional diameter exceeds 10, the formation of new bone around the filling material will be slow, while if it is less than 0.2 m, the filling material will not absorb blood, etc. It is washed away and does not stick to the filling area,
This is not preferable because a sufficient cremation effect cannot be expected. It is essential that the cylindrical or polygonal cylindrical calcium phosphate compound filler used in the present invention have substantially the same cross-sectional shape from the operational standpoint. Furthermore, when filling bone defects and bone debris, the ratio of length to cross-sectional diameter must be in the range of 0.1 to 10 in order to inject to a sufficient depth.

The cylindrical or polygonal cylindrical calcium phosphate compound filler that can be used in the present invention may preferably be either densely fired or porous. It may also be used in combination with substances that can further improve the osteogenic potential, such as osteogenic factors and/or fibrin.

In the present invention, particles made of a calcium phosphate compound are used, but if such particles are obtained by a dry method or natural particles are used, after pulverization, a binder solution such as polyvinyl alcohol or methylcellulose is added to the calcium phosphate compound powder. to a suitable plastic state, and then extrusion molded into a desired cylinder or polygon using an extruder such as a twin-screw granulator, followed by firing at a temperature of 700 to 1200°C.
It can be manufactured by firing at.

On the other hand, for those obtained by the wet method and hydrothermal method, the calcium phosphate compound slurry is dried as it is,
Particles of the calcium phosphate compound can then be obtained by crushing, or after crushing, the above-mentioned binder solution can be added to the powder to make it into an appropriate plastic state, and the powder can be shaped into cylinders or polygonal cylinders in the same manner as described above, and then fired. It can also be obtained by

The cylindrical or polygonal columnar calcium phosphate compound filler used in the present invention may be attached directly to the injection device, but filling can be carried out more easily.

In addition, in order to avoid the need to take the injection device in and out of the bone defect area and bone atomization area of the living body many times and to shorten the time required for surgery, for example, the injection device may be introduced into a predetermined holder in advance, and the holder may be inserted into the holder. The material of the holder, which is preferably used in the injection device, is preferably a sterilizable material from the viewpoint of surgical safety. For example, it is preferable to use a holder made of polypropylene or polyethylene.

<Examples> Hereinafter, the present invention will be explained in more detail using examples.

The dried product of hydroxyapatite produced by the wet method was crushed, and the average particle size was reduced to 0 using a polyvinyl alcohol solution.
．． 5 to 1.0++a, it is formed into a cylinder with a grain surface diameter of 21III and a length of 31m using a twin-screw granulator, and then fired at 950°C to produce hydroxyapatite in the form of a cylinder with the same cross-sectional shape. A particle cloth filling material was obtained. The obtained filling material was loaded into a filling syringe and injected into the bone defect and coarse bone, and the filling operation was smooth and the treatment results were good.

A hydroxyapatite particle cloth filling material was produced in the same manner as in Example 1, except that the rear and direction cross-sectional shapes of the Kaikasa Goko particles were not substantially the same but irregular, and the major axis diameter was 2 orm.
Next, an attempt was made to fill the obtained filling material using a filling syringe in the same manner as in Example 1, but it became clogged and filling injection was impossible. A filling material for bone defects and osteoporosis containing a calcium phosphate compound can be easily filled in a predetermined amount into the affected area, and is effective in the treatment of osteoporosis, which has until now been considered difficult to cure completely. be able to. Furthermore, the filling material according to the present invention can be easily and properly filled deep into a living body, and the incision can be made extremely small.

Claims (1)

[Claims] A cylindrical or polygonal cylindrical filling material containing a calcium phosphate compound, characterized in that the cross-sectional shape of the filling material is substantially the same, and the ratio of length to cross-sectional diameter is in the range of 0.1 to 10. Filling material for bone defects and osteoporosis.