JPS59189841A - Sealing gasket for filling bone carnal - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sealing stopper for an intramedullary cavity comprising a calcium phosphate compound.

Conventionally, in the field of orthopedics, when it is necessary to replace the joint at the junction of the femur and pelvis, a hip joint equipped with a stem is used, and the stem is inserted and fixed into the medullary cavity of the femur. However, in this case bone cement is usually used to fix the stem. At this time, the hip joint should naturally be operated in such a way that it can withstand long-term use, and the inserted stem and bone cement, as well as the bone and bone cement on the inner surface of the medullary canal, should be sufficiently compressed, and the irregularities on the surface of the stem should be properly bonded. It is preferable to press-fit the bone cement and prevent the presence of bodily fluids etc. between the bone on the inner surface of the medullary cavity and the bone cement as much as possible. However, in the current surgical method, when the stem is inserted, the bone cement is pushed out in the direction of insertion of the stem into the medullary canal, and it cannot be said that sufficient pressure fixation is achieved. On the other hand, it may be possible to achieve sufficient crimp fixation by filling the entire bone marrow cavity with bone cement, but in this case, the amount of bone cement used would be extremely large, making it uneconomical. In addition, since bone cement is a foreign substance to living organisms, there is a high possibility that it will harm living organisms if large amounts of this substance are used in important biological parts such as the bone marrow cavity.

In addition, - to fill the intramedullary cavity as a sealing plug,
For example, it is conceivable to cut out the cancellous bone existing in the head of the resected femur to the required size and use it, but this cutting would have to be done during the surgery, which would increase the burden on the surgeon during the surgery. In addition, in patients who require surgery, the femoral head often does not have enough normal cancellous bone to fill it, and it may not be possible to perform it even if it is desired. There are also many.

In view of these circumstances, the present inventors have conducted various studies to eliminate these drawbacks, and have completed the present invention.

That is, the main purpose of the present invention is to create a medullary canal which, when a hip joint or the like is used in the field of orthopedics, provides sufficient compression between the stem of the hip joint and bone cement, and between the bone and bone cement to further strengthen the fixation. The purpose of the present invention is to provide a sealing stopper for Naikoten.

Another object of the present invention is to provide a sealing stopper for intramedullary optics that does not cause any inflammatory reaction even if it remains in the medullary cavity for a long period of time and has excellent biocompatibility.

According to the present invention, there is provided a sealing stopper for an intramedullary cavity, which is made of a calcium phosphate compound and has a compressive strength of 500 kg/c+++ or more.

The present invention will be described in detail below.

Various materials such as metal materials, organic materials, alumina, etc. can be used as the sealing plug for the intramedullary cavity photoluminescence of the present invention, but since it exists in the medullary cavity for a long period of time, calcium phosphate is used due to its biocompatibility. Compounds are suitable.

Calcium phosphate compounds used in the present invention include tricalcium phosphate, hydroxyapatite, tetracalcium phosphate, oxyapatite, calcium birophosphate,
Examples include fluoroapatite, a compound in which a portion of the hydroxyl group of hydroxyapatite is replaced with a fluorine ion or an oxygen ion, and a mixture thereof. Of these,
Examples of materials that do not cause an inflammatory reaction and have excellent biocompatibility include tricalcium phosphate, hydroxyapatite, tetracalcium phosphate, oxyapatite, fluoroapatite, and mixtures of one or more of these.
It is preferable to use these compounds or mixtures.

The sealing plug for intramedullary cavity optic tube of the present invention is inserted into the medullary cavity slightly deeper than the length of the stem part, and the filling sealing plug allows the pressure of the bone cement due to the insertion of the stem part to be directed in the direction of insertion of the stem part. This prevents the i lf of the stem and the bone cement, and the bone and the bone cement, thereby making the fixation of the lower part, particularly the hip joint, stronger. For this reason, the sealing plug for intramedullary cavity optic tube of the present invention must be able to be inserted into the medullary cavity and must be capable of receiving sufficient pressure from the bone cement from the insertion direction of the stem portion. For that purpose, the filling sealing plug should be 500kg/cliJ or more, preferably 800kg/cliJ or more.
g/c++f or more, more preferably 1200kg/
It is necessary to have a compressive strength of c++r or more. This is because if the compressive strength is less than 500 kg/at/, it often breaks when inserted into the medullary cavity, or even if it does not break, it cannot sustain sufficient pressure.

The type of sealing plug for intramedullary canal optics of the present invention is such that when inserted deeper into the medullary canal than the length of the stem, it is possible to push something slightly larger than the inner diameter of the medullary canal. It is necessary to have a shape that can accept pressure from bone cement from any direction. For this purpose, a shape such as a truncated cone or a combination of a truncated cone and a cylinder is given as an example. In this case, especially if a cylindrical projection is formed on the bottom side of the truncated cone, etc., this projection can be attached and fixed to the cylindrical end of a stainless steel pipe, etc., so that it can be filled more accurately deep into the medullary cavity. I can do it. Of course, if the stem portion is short and there is no need to make a cylindrical hole in the medullary cavity, it is also possible to use a shape that can be adapted to the shape of the medullary cavity. Any shape other than the above-mentioned examples may be used as long as it can be fixed at a predetermined position within the bone marrow cavity when pressure is applied by the bone cement when inserting the slam portion.

The method for manufacturing the intramedullary cavity optical fiber of the present invention can be made by preparing a sintered body of calcium phosphate compound in advance and processing the sintered body. It can also be produced by pressure molding using a rubber press or the like, or by processing it into a predetermined shape after firing using a lathe or the like after molding, and then firing.

The present invention will be specifically described below with reference to Examples.

[Example 1] A hole with a diameter of 9+++ m was made in the femur of a slaughtered cow, and a truncated cone (a truncated cone with a base diameter of 10 cm) made of hydroxyapatite, tricalcium phosphate, and fluoroapatite, which had the compressive strength of the heel, was drilled in the femur of a slaughtered cow. , upper surface diameter 8+w+n, height 5mm) were inserted into each sample, and the presence or absence of breakage during insertion and the number of broken samples were also examined in the opposite direction to the direction of insertion with a force of 50kg/cn+ for those that were successfully inserted. The presence or absence and number of 9 pieces that came out from the femur of the dried sample were examined. Here, the compressive strength was measured using a universal testing machine (manufactured by Instron) using a sample of 5 mm φ x 5 m+n L, and the results are shown in Table 1.

(Margins below) Table 1 [Example 2] Immediately after slaughter, the proximal head of the frozen dog's femur was excised, bone cement was placed in the bone marrow, and the diameter of the femur was 5 mm.
A stainless steel rod of 20 lengths with a file-like surface was pushed into the bone cement in the bone marrow by 4cIT+, and the bone marrow was excised in the same manner, and a hole with a diameter of 5 m was made in the length direction of the bone marrow. Bottom diameter 5.5 cylinder, top diameter 4.5+++
A sample made of hydroxyapatite with a compressive strength of 1200 kg/d and having a height of 3 m was inserted from the top direction, and then bone cement was put in.
A stainless steel rod with a file-like surface of 4 cm was inserted into the bone cement in the bone marrow, and the non-inserted side of the stainless steel rod and the femur were held in the chuck of a universal testing machine (manufactured by Instron). A tensile test was attempted. As a result, when hydroxyapatite was not inserted into the bone marrow, it peeled off at the interface between the bone and bone cement with a force of 30 kg/c++, whereas when hydroxyapatite was used, the force was 60 kg/c++r. No peeling occurred at the joint surface.

[Example 3] Tricalcium phosphate with a size of 3 x 3 x 3 mm (compressive strength 1200 kg/cul) was placed in the femoral bone marrow of a dog
l, hydroxyapatite (1450kg/c++
+), tetracalcium phosphate (1110 kg/cal
l, fluoroapatite (1200 kg/c/)
, and a mixture of hydroxyapatite and oxyapatite (2530 kg/c++r) were implanted, and after 6 months, each sample was ra11! I conducted an investigation. the result,
No inflammatory reaction was observed around the sample in any of the samples, and the biocompatibility was also good.

patent applicant Mitsubishi Mining Cement Co., Ltd. Procedural amendment (voluntary) May 17, 1981 Commissioner of the Patent Office Kazuo Wakasugi 1 Display of incident 1981 Patent Application No. 61539 2 Name of the invention Sealing stopper for intramedullary cavity light bulb 3 Person making the amendment Relationship to the case Patent applicant Mitsubishi Mining Cement Co., Ltd. 4 agents “Detailed Description of the Invention” section of the specification 6 Contents of amendment

Claims (1)

[Claims] Made of calcium phosphate compound, compressive strength is 500k
1. A sealing stopper for intramedullary cavity optics, characterized by having a strength of g/cII or higher.