JP2002371007A - Artificial synovia - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a new artificial synovia replacing sodium hyaluronate. SOLUTION: This artificial synovia comprises dipalmitoylphosphatidylcholine(DPPC) and fibronectin(FN). Both DPPC and FN form films on the surfaces of joint cartilages in a joint and a cluster of sodium hyaluronate in the synovia of the joint exists in a nipped state between the films of DPPC and FN. By the structure, the artificial synovia which sufficiently protects the surface of the joint in the action of the joint and extremely reduces a longitudinal vibration occurring in a contact or a sliding of cartilages with each other may contain sodium hyaluronate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an artificial synovial fluid used for lubricating a living joint, and more particularly, to an artificial synovial fluid having low carcinogenicity and capable of suppressing joint wear.

[0002]

2. Description of the Related Art A living joint is capable of functioning without replacement for about 70 years while undergoing a variable load of several times the body weight more than 5,000 times a day, which cannot be performed by an artificial object. It has. In the lubricating mechanism, a squeeze fluid lubricating film is generated by applying a variable load to a natural lubricating fluid called a synovial fluid, thereby preventing direct contact of the friction surface and maintaining a good lubricating state. The living joint reduces wear by such a lubrication mechanism. Reducing wear is one of the goals of lubrication. The lubrication mechanism in the artificial joint includes the following.

(1) Fluid film lubricatio
n): A lubrication state in which a fluid film that is sufficiently thicker than the surface roughness is formed between the friction surfaces and the friction surfaces are completely separated by the pressure of the fluid. (2) Boundary lubrication: A lubrication state in which an adsorbed molecular film (boundary film) of about one or several molecular layers is formed between friction surfaces, and the adsorbed film is separated. (3) Mixed lubrication: A boundary lubrication state in which boundary lubrication, fluid lubrication, and dry friction coexist and are actually observed.

[0004] Although the above three types of lubrication mechanisms are considered in artificial joints, living joints are mostly controlled by fluid lubrication. However, it is difficult for current artificial joints to perform fluid lubrication depending on the type, and many of them are based on boundary lubrication or mixed lubrication. While the friction coefficient of a living joint is 0.005 to 0.01, an artificial joint that assumes boundary lubrication or mixed lubrication has a friction coefficient of 0.05 or more, which is 5 to 10 times that of a living joint. As described above, in an artificial joint in which a frictional surface is in direct contact or a lubricating state close to direct contact, wear of the contact portion is likely to occur, which is a very serious problem.

There are four basic forms of wear. (1) Adhesive wear: Wear caused by shearing or breaking of the adhesive part that constitutes the true contact area of the friction surface. (2) Abrasive wear: Abrasion caused by a cutting action that occurs when one of the friction surfaces is hard or a hard foreign material is present between the friction surfaces. (3) Corrosive wear: Wear caused by the combination of corrosion and the mechanical action of friction caused by the chemical reaction between the friction surface and highly reactive components in the atmosphere. (4) Fatigue wear: Wear caused by rolling and pitting or flaking.

[0006] Most of actual wear phenomena are rarely caused by one wear mode, and are considered to be caused by a combination of a plurality of wear modes. It is considered that the wear of the artificial joint is also caused by a combination of several forms of wear.

[0007] In all of fluid lubrication, boundary lubrication, and mixed lubrication, lubrication is established by the interposition of synovial fluid between friction surfaces. In order to reduce the wear of the artificial joint, the properties of the synovial fluid cannot be neglected. In living joints,
Synovial fluid and cartilage matrix commonly contain hyaluronic acid, protein components, and lipid components. It has been reported that lamina splendens exists in the outermost layer of articular cartilage, and that synovial fluid (articular fluid) and articular cartilage are continuous through a layer rich in hyaluronic acid. It is believed to have a structure. From the observation of the bright plate by electron microscopy, the bright plate is poor in collagen tissue, but a remarkably high concentration of hyaluronic acid exists in a honeycomb structure, and the high concentration of hyaluronic acid is 50 to 100 μm in the first layer of cartilage. Some report that it extends to depth. The fact that the synovial fluid and the friction surface have a common component, that is, the boundary between the cartilage and the synovial fluid is unclear and continuous, is one of the excellent friction and wear characteristics of a living joint under boundary lubrication and mixed lubrication. It is thought to be the cause. Further, judging from the low friction coefficient of the living joint, it can be said that synovial fluid is an extremely excellent lubricant. Synovial fluid in a living body is a viscous, transparent liquid that is colorless or pale yellow, and its role is synovial fluid (agent), which is a nutrient source for articular cartilage.

[0008]

Conventionally, treatment for intraarticular injection of a physiological saline containing sodium hyaluronate has been performed for joint diseases such as osteoarthritis and rheumatoid arthritis, and for joint wounds. Have been. This is because sodium hyaluronate is contained in a living joint as described above and functions as a joint lubricant.

In joints that have caused severe dysfunction,
Functional restoration methods by artificial joint replacement have been widely applied. In this case, in the hip joint, only the femoral head may be replaced with an artificial head, or only the acetabular part of the pelvis may be replaced with an artificial object called a socket, depending on the degree of the obstacle. At this time, ultrahigh molecular weight polyethylene (hereinafter abbreviated as UHMWPE) is widely used as a material for the socket for artificial joint. However, when only the acetabular part or only the bone head of the hip joint is replaced with an artificial product, if good lubrication cannot be obtained, the burden on the acetabular part or the head of the bone increases. Furthermore, when both the acetabular part and the bone head are replaced with artificial materials, a large amount of abrasion powder is mainly generated from the socket part, which may have harmful effects on the living body. For this reason, administration of an aqueous solution of sodium hyaluronate is also performed on artificial joints for the purpose of improving and improving lubrication performance. Sodium hyaluronate forms clusters in water, and the aqueous solution of sodium hyaluronate has viscosity due to the resistance of the clusters.

However, it has been studied that excessive administration of sodium hyaluronate is carcinogenic, and the number of uses thereof is generally limited. Therefore, there is a demand for a new synovial fluid for a joint that replaces sodium hyaluronate in both a living joint and an artificial joint of a patient.

An object of the present invention is to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a novel artificial synovial fluid that replaces sodium hyaluronate. Another object of the present invention is to provide an artificial synovial fluid capable of reducing wear and longitudinal vibration of cartilage of a joint.

[0012]

According to the present invention, there is provided an artificial synovial fluid comprising dipalmitoyl phosphatidylcholine and fibronectin. The present inventor has found, through research activities different from the present invention, that the cause of the disease due to joint fatigue is caused by longitudinal vibration of the cartilage forming the joint or of the sliding portion of the artificial joint. Dipalmitoyl phosphatidylcholine (hereinafter referred to as “dipalmitoyl phosphatidylcholine”), a type of phospholipid, is an artificial synovial fluid component that can reduce longitudinal vibration.
"DPPC") and fibronectin (hereinafter, referred to as "DPPC").
(Abbreviated as "FN") was found to be extremely effective. As shown in the conceptual diagram of FIG.
Both PPC and FN form a film on the surface of the cartilage of the joint, and sodium hyaluronate (hereinafter, referred to as “the synovial fluid”) in the synovial fluid of the joint.
Clusters (abbreviated as HA) exist so as to be sandwiched between the films. It is considered that such a structure sufficiently protects the surface of the cartilage during the operation of the joint and significantly reduces longitudinal vibration generated when the cartilage contacts or slides with each other. At this time, in particular, it is considered that DPPC forms a lipid bilayer on the surface of cartilage and causes stable slip, while FN prevents cartilage surface from being roughened for a long period of time by strengthening chondrocytes. It is considered that the longitudinal vibration is significantly reduced due to the synergistic effect thereof. As a result, it is possible to prevent a disease occurring in the joint and to relieve pain of a patient having the disease in the joint. By using the artificial infusion of the present invention, it is no longer necessary to use HA, which has been limited in the number of uses, and it is possible to avoid the carcinogenicity of patients based on the use of HA. In addition, the artificial liquid of the present invention may further contain HA,
In this case, the use amount of HA can be minimized because DPPC and FN are contained.

The synovial fluid of the present invention typically contains DPPC and FN dissolved in physiological saline. In synovial fluid, DPPC may be included at a content of 0.001 to 0.1% by weight. In the synovial fluid, fibronectin was 0.001 to 0.05.
% By weight.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below, but the present invention is not limited to these embodiments.

The synovial fluid of the present invention has a DPP as shown below.
It can be prepared by adding and dissolving C, FN and HA in physiological saline at a predetermined ratio. Hereinafter, individual additives and the like will be described.

[Dipalmitoyl phosphatidylcholine (D
PPC)] DPPC (Dipalmitoyl phosphatidilcholin
e) is Dipalmitoyl lecithi
Also called n), it is one of the phospholipids (phospholipids). As shown in FIG. 2, DPPC is composed of palmitic acid (CH ₃₎ in which the first and second positions of glycerol are saturated fatty acids.
(CH ₂ ) ₁₄ COOH). DPPC has an extremely strong function as a surfactant among phospholipids. By this function, cells that try to take a nearly spherical shape that is stable in energy are kept flat. By injecting the synovial fluid of the present invention into a joint of a human body, a lipid bilayer membrane of DPPC is formed on the joint surface as shown in FIG. 1, and this membrane is considered to realize low friction. In the synovial fluid of the present invention, DPPC is 0.001 to 0.
It can be included at a content of 1% by weight. In particular, from the viewpoint of excellent vibration damping properties and wear resistance, 0.01 to 0.2.
1% by weight is preferred.

[Fibronectin (FN)] FN (Fibron
ectin) is a glycoprotein having a molecular weight of about 460,000 present on the cell surface of animals, connective tissues, blood and the like. FN has a site that binds to collagen, fibrin, fibrinogen, and the like. It is considered that FN adheres to the surface of the cartilage of the joint as shown in FIG. 1 to provide a boundary lubrication effect specific to glycoprotein. For this reason, it is thought that wear and vibration of articular cartilage are reduced together with DPPC in synovial fluid. In the synovial fluid of the present invention, FN can be contained at a content of 0.001 to 0.05% by weight. In particular, 0.01 to 0.05% by weight is preferable from the viewpoint of excellent vibration damping properties and wear resistance.

[Sodium hyaluronate (HA)] HA
(Hyaluronic Acid sodium salt) has a structure as shown in FIG. 3 and has a molecular weight of about 800 to 2.4 million, and is mainly used for joints of patients with chronic joint diseases (osteoarthritis, rheumatoid arthritis, etc.). It is used for the purpose of improving and improving lubrication performance. HA is one of seven polysaccharides classified as glycosaminoglycans. Unlike other glycosaminoglycans, they do not have a sulfate group and often serve as a backbone to bond other glycosaminoglycans to their side chains to form a huge proteoglycan complex. HA is widely distributed in various animal tissues, particularly in mesenchymal tissues, and is abundantly present in the vitreous, aqueous humor, umbilical cord, synovial fluid, dung membrane fluid, skin, chicken cockscomb, and the like. Also, H
A is an amorphous solid and has the physical property of hygroscopicity. It is dissolved in water as an acid or salt with a polymeric polybasic acid and hydrates to form micelles with each other. Is shown. In addition, the presence of metal ions makes it easy to form a gel. The viscosity varies depending on the production method, and varies greatly depending on the presence of the electrolyte, and precipitates at a pH of 3 or less. Further, the biological properties of HA are considered to be a conjugate substance that forms a gel in animal tissues as a free acid and salt and fills between cells and between fibers, and binds them. In addition, its high viscosity is important in preventing bacterial invasion and toxicant infiltration, and in these respects it is equivalent to pectic substances in plants.

As described above, HA is originally present in the synovial fluid of a living joint.
It can be included at a content of 0.1% by weight. In this case, since the synovial fluid of the present invention contains FN and DPPC, the usage of HA can be significantly reduced.

[Ultra high molecular weight polyethylene (UHMWP)
E)] The socket of the artificial joint is made of ultra high molecular weight polyethylene (UHMWPE: Ultra High Molec) having a molecular weight of several millions.
ular Weight Polyethylene) is used. UHMWP
E is a crystalline high-performance thermoplastic material having excellent abrasion resistance, impact resistance, chemical resistance, and the like. The melting point is as low as about 140 ° C., but there are disadvantages such as that injection molding is somewhat difficult. It is one of the least abraded materials when sliding at a relatively low speed near room temperature. Particularly tough and impact resistant, it has strong properties against abrasive wear. UHMWPE, like PTFE, has a linear molecular structure and a relatively small bonding force between molecules, and tends to form a molecular alignment layer on the surface by sliding. It is thought to show.
For this reason, UHMWPE is often used for sliding parts of artificial joints.

Examples (1) Preparation of Samples As samples of synovial fluid, DPPC, FN and HA were dissolved in physiological saline at the ratios shown in FIGS. Individually prepared.

HA (H603: manufactured by Tokyo Kasei Kogyo Co., Ltd.) was used as the HA, which had been separated from the cockscomb by the improved DASwann method, purified and freeze-dried. This HA has a white cotton-like appearance and a molecular weight of 600,000 to 800,000 (measured by a viscosity method). Specific rotation [α] ²⁰ D = about −60 ° (C = 0.
_1, H 2 O). From this HA, the presence of proteins and amino acids was not detected through the ninhydrin reaction. Infrared absorption spectrum analysis revealed that chondroitin sulfate was not present.

As the DPPC, DPPC having a purity of 99.9% (purity measured by a thin layer chromatography method) manufactured by Kanto Chemical Co., Ltd. was used. In addition, Sigma-Aldrich Japan Co., Ltd. FN having a purity of 95% (purity measured by high performance liquid chromatography) and a protein content of about 70% was used as the FN.

The physiological saline is manufactured by Otsuka Pharmaceutical Co., Ltd. in China.
The composition is 9 g of sodium chloride in 1000 ml,
Specific gravity was 1.006 and pH was about 6.4. The electrolyte composition was 154 mEq / L for both Na ⁺ and Cl ⁻ .

(2) Longitudinal Vibration and Abrasion Amount Measurement Experiment The 44 samples of the synovial fluid prepared as described above were subjected to a longitudinal vibration measurement experiment as follows. In this test, a socket made of ultra-high molecular weight polyethylene (UHMWPE) was used as a socket for an artificial joint, and a pig hip head as a head. UHMWPE (UH900) has a diameter of 40
mm and a 4 mm thick socket. This UHMW
The mechanical properties of PE (UH900) are shown in the table of FIG.

FIG. 7 is a schematic diagram of a reciprocating friction and wear test apparatus used in the experiment. Using this test apparatus, a reciprocating sliding friction wear test was performed to measure longitudinal vibration and wear amount. There are various types of motion when performing a wear experiment, but since this experiment is a friction and wear experiment of a joint, a one-way reciprocating sliding motion is performed to make it very similar to the actual joint motion A form of friction was adopted.

In this apparatus, the UHM processed as described above is used.
The WPE socket 7 is fixed to the bottom of a container 9 filled with the synovial fluid sample 6, and the container 9 is connected to a carriage 8 that reciprocates horizontally. The pig hip joint head 5 attached to the tip of the column 10 is arranged so as to be in contact with the socket 7. The load 1 is applied to the pig hip joint head 5 via the support 10.
Is added to Prop 10 holding pig hip joint head 5
Since the vertical direction of the head is unrestricted, the table connecting the socket 5 is reciprocated to move the pig hip joint head 5 and the socket 7.
Sliding friction can be caused between them. Using a non-contact laser displacement meter 2 to measure the displacement of the column 10,
The total displacement of both the pig hip joint head 5 and the socket 6 was defined as the total wear. In this method, the average wear depth between the head and the socket, that is, the sum of the average wear depths of the head and the socket can be directly obtained. The minimum resolution of the laser displacement meter 2 used is 0.0001 mm, and the response time is 1 ms. Further, the longitudinal vibration of the support system can be measured by the strain gauge 3 attached to the support 10 in the vertical direction, and the measured vibration signal can be analyzed for each frequency by FFT (not shown).

An experiment was conducted as follows using the above-described apparatus. First, the surface of the UHMWPE socket 7 was washed with acetone and dried sufficiently. The pig hip joint head 5 and the socket 7 were attached to the experimental apparatus shown in FIG. 7, and a sample of synovial fluid was poured into the container 9 and a load of 200 N was applied.
The slide 8 was reciprocated at a sliding speed of 4 cm / sec to give sliding friction. The slip distance of one round trip was 2 cm (1.8 round trips / second). The total time of the sliding experiment was 4
In order to determine the total amount of wear, the displacement in the direction perpendicular to the sliding surface was measured every 30 minutes for 1 minute. here,
Since the height of the strut fluctuated due to the vertical movement of the head, an average was obtained, and the difference between the average displacement at the start of the experiment and the average displacement after 4 hours was defined and used as the total wear. The longitudinal vibration was measured at the time of measuring the total wear. The atmosphere temperature of the experimental apparatus was maintained at about 30 ° C.

(3) Result of longitudinal vibration measurement Vibration was measured by a frequency analysis of 0 to 10 by FFT.
The longitudinal vibration displacement at a frequency of 0 Hz was observed. FIG.
Shows, as an example, a waveform of a main component frequency of longitudinal vibration displacement obtained in an experiment of synovial fluid in which 0.001 wt% DPPC is dissolved in physiological saline. Two main component frequencies are seen, about 0.25 Hz and about 80 Hz. According to the calculation of the natural frequency, the peak at about 0.25 Hz is the natural frequency of the leaf spring, and the peak at about 80 Hz is the natural (resonant) frequency unique to the column. Since it is considered that the vibration of the strut affects the wear, the peak of the vibration frequency of around 80 Hz, which is the natural frequency of the strut, is observed to determine the magnitude of the relative longitudinal vibration between the pig hip joint head 5 and the socket 7. I considered.

9 to 19 show the experimental results. As the magnitude of the longitudinal vibration amplitude, the ratio (longitudinal vibration displacement ratio) of the vibration amplitude (comparative reference) of each synovial fluid sample to the vibration amplitude of synovial fluid containing only physiological saline was used. Note that the average value of the plurality of amplitude measurement data is used for the comparison reference and the vibration amplitude of each sample as described above. FIG. 9 shows that no HA was added (HA: 0.0
6 is a graph showing the relationship between the change in the DPPC and FN concentrations and the displacement ratio of the longitudinal vibration amount in the case of (wt%). From FIG. 9, D
In the case of PPC alone (FN: 0.0wt%), the longitudinal vibration displacement ratio is in the range of 0.8 to 0.95, and the vibration amplitude of the synovial fluid containing only physiological saline (longitudinal vibration displacement ratio 1) .
It can be seen that the vibration amplitude is slightly lower than 0).
It can be seen that the longitudinal vibration amount displacement ratio decreases steeply and one-dimensionally with an increase in the FN concentration. And
It can be seen that when the FN concentration is 0.046 wt%, the longitudinal vibration displacement ratio drops to a value of about 0.1 regardless of the DPPC concentration. On the other hand, the longitudinal vibration amount displacement ratio does not change much with the change in the DPPC concentration. Therefore, D without HA
It can be seen that in the PPC / FN synovial fluid, the longitudinal vibration amount displacement ratio greatly depends on the FN concentration.

FIGS. 10 to 12 show that HA is 0.1 watts each.
It is a graph which shows the relationship of the longitudinal vibration amount displacement ratio with respect to the change of DPPC and FN density | concentration at the time of making t%, 0.3wt%, and 0.5wt% constant values. From FIGS. 10 and 11, HA
9 is 0.1 wt% and 0.3 wt%, the longitudinal vibration amount displacement ratio decreases as the FN concentration increases, as in the case of FIG. 9. Further, according to FIG.
Is 0.5 wt%, and if either DPPC or FN is present, the longitudinal vibration displacement ratio is approximately 0.1%.
It turns out that it was suppressed to 3 or less.

FIG. 13 shows that no FN is added (FN: 0.
6 is a graph showing the relationship between the change in the HA and DPPC concentrations and the displacement ratio of the longitudinal vibration amount in the case of 0 wt%). It can be seen that the longitudinal vibration amount displacement ratio generally decreases as the HA concentration increases. On the other hand, it can be seen that the longitudinal vibration amount displacement ratio does not relatively change with the change in the DPPC concentration. Further, it can be seen that the amount of longitudinal vibration is effectively suppressed when HA is 0.2 wt% or more. Comparing the results of FIG. 13 with the results of FIG. 9, it can be seen that FN can substitute for HA in the synovial fluid containing DPPC. This also means
FN was 0.02 wt% and 0.046 wt%, respectively.
14 and 15 showing the relationship between the change in the HA and DPPC concentrations and the change ratio of the longitudinal vibration amount when the constant value
It can also be seen by comparing it with 3. In particular, FIG.
5, the FN concentration was relatively high (0.0
46wt%), if it is contained, it will be 0.1% regardless of the amount of HA.
It can be seen that an extremely low longitudinal vibration displacement ratio of about 1 to 0.2 is achieved. In addition, it should be noted that the amount of change in FN for achieving the longitudinal vibration displacement ratio obtained when HA is used alone is one order of magnitude smaller than the amount of change in HA.

FIGS. 16 to 19 show the DPPC,
It is a graph which shows the relationship of the longitudinal vibration amount displacement ratio with respect to the change of HA and FN density | concentration at the constant value of 0.0wt%, 0.001wt%, 0.01wt%, and 0.1wt%. 16 and FIG. 17 to FIG. 19, it can be seen that, in general, when three components of DPPC / HA / FN are present, the displacement of the longitudinal vibration amount is larger than in the case of two components of HA / FN or only one component. It can be seen that the composition range in which the ratio can be reduced to, for example, 0.3 or less is expanded. Also, FIG.
From the result of FIG. 19, it can be seen that when three components of DPPC / HA / FN are present, the higher the concentration of each component, the lower the longitudinal vibration displacement ratio can be. This is because of the intervention between the frictional surfaces of the HA clusters subdivided as shown in FIG. 1, the formation of a lipid bilayer of DPPC on the surface of the head, and the prevention of roughening of the cartilage surface based on the strengthening of chondrocytes by FN. It is thought to be due to a synergistic effect with the action.

(4) Results of measurement of wear amount FIG. 20 shows that no DPPC was added (DPPC: 0.00
6 is a graph showing the relationship between the change in the HA and FN concentrations and the amount of wear (mm) in the case of 0 wt%). From this graph, in the case of HA alone (HA: 0.5 wt%, FN: 0.
(0 wt%), the wear amount reaches 0.35 mm. FIG. 21 shows that no HA was added (HA: 0.0 wt.
%) Is a graph showing the relationship of the amount of wear (mm) with respect to changes in DPPC and FN concentrations in the case of (%). In the case of the combination of FN / DPPC, regardless of the mixing ratio, the wear amount is the case of HA alone in FIG. 20 (HA: 0.5 wt%, F
N: 0.0 wt%).

From the above, it can be seen that when the synovial fluid is composed of FN / DPPC, both longitudinal vibration and abrasion can be reduced as compared with the case where HA is used alone.
Furthermore, it can be seen that when the synovial fluid is composed of FN / DPPC / HA, abrasion can be further suppressed.

[0036]

The synovial fluid composed of the FN / DPPC of the present invention can effectively suppress the longitudinal vibration of the cartilage of a living joint, which occurs during the operation of the joint, as compared with the synovial fluid composed of conventional HA. Therefore, it is extremely effective for treatment and prevention of joint diseases. The present invention is also very useful for an artificial joint using a UHMWPE socket. In the synovial fluid of the present invention, HA
Can be used or the amount thereof can be reduced, so that the rate of carcinogenesis due to injection of synovial fluid can be significantly reduced.

[Brief description of the drawings]

FIG. 1 is a schematic diagram for explaining the functions of DPPC, FN and HA in synovial fluid of the present invention.

FIG. 2. Dipalmitoyl phosphatidylcholine.
It is a structural formula of (DPPC).

FIG. 3 is a structural formula of sodium hyaluronate (HA).

FIG. 4 is a table showing compositions of samples prepared in Examples.

FIG. 5 is a table showing compositions of samples prepared in Examples.

FIG. 6 is a table showing mechanical properties of UHMWPE used in Examples.

FIG. 7 is a conceptual diagram of an apparatus used for a test in an example.

FIG. 8 shows 0.001 wt% DP in saline.
The longitudinal vibration displacement obtained in the experiment of the synovial fluid in which PC was dissolved
9 is a chart showing the result of T analysis.

FIG. 9 shows that no HA was added (HA: 0.0 wt.
%) Is a graph showing the relationship between the change in the DPPC and the FN concentration and the displacement ratio of the longitudinal vibration.

FIG. 10 is a graph showing the relationship between the change in the DPPC and the FN concentration and the displacement ratio of the longitudinal vibration amount when the HA is 0.1 wt%.

FIG. 11 is a graph showing the relationship between the change in the DPPC and FN concentrations and the displacement ratio of the longitudinal vibration amount when HA is set to 0.3 wt%.

FIG. 12 is a graph showing the relationship between the change in the DPPC and FN concentrations and the displacement ratio of the longitudinal vibration amount when HA is set to 0.5 wt%.

FIG. 13 shows that no FN was added (FN: 0.0
4 is a graph showing the relationship between the change in the HA and DPPC concentrations and the displacement ratio of the longitudinal vibration amount in the case of (wt%).

FIG. 14 is a graph showing the relationship between the change in the HA and DPPC concentrations and the change in the longitudinal vibration amount displacement ratio when the FN concentration is 0.02 wt%.

FIG. 15 is a graph showing a relationship between a change in the longitudinal vibration amount and a change in the HA and DPPC concentrations when the FN concentration is 0.046 wt%.

FIG. 16 is a graph showing a relationship between a longitudinal vibration amount displacement ratio and a change in HA and FN concentrations when DPPC is not included.

FIG. 17 is a graph showing the relationship between the change in the HA and FN concentrations and the displacement ratio of the longitudinal vibration amount when the DPPC is set to 0.001 wt%.

FIG. 18 is a graph showing the relationship between the change in the HA and FN concentrations and the change ratio of the longitudinal vibration amount when the DPPC is set to 0.01 wt%.

FIG. 19 is a graph showing the relationship between the change in the HA and FN concentrations and the displacement ratio of the longitudinal vibration when the DPPC is set to 0.1 wt%.

FIG. 20 is a graph showing the relationship between the change in HA and FN concentrations when DPPC is not included and the amount of wear.

FIG. 21 is a graph showing the relationship between changes in DPPC and FN concentrations when no HA is included, and the amount of wear.

[Explanation of symbols]

 Reference Signs List 1 load 2 laser displacement meter 3 strain gauge 5 pig hip joint head 6 socket 8 carriage

Continued on front page F-term (reference) 4C076 AA12 CC09 CC26 DD23 DD63 FF43 4C084 AA02 BA34 BA44 MA02 MA05 MA56 ZA96 4C086 AA01 AA02 EA25 MA02 MA03 MA05 MA17 MA56 NA14 ZA96

Claims (5)

[Claims] 1. An artificial synovial fluid for living joints, comprising fibronectin and dipalmitoyl phosphatidylcholine. 2. Fibronectin is added in an artificial synovial fluid at a concentration of 0.00
The artificial synovial fluid according to claim 1, comprising 1 to 0.05% by weight. 3. The artificial synovial fluid according to claim 1, comprising 0.001 to 0.1% by weight of dipalmitoyl phosphatidylcholine. 4. The artificial synovial fluid according to claim 1, further comprising sodium hyaluronate. 5. The above-mentioned dipalmitoyl phosphatidylcholine 0.001-0.1% by weight, fibronectin 0.0
01-0.05% by weight and sodium hyaluronate 0.
3. The artificial synovial fluid according to claim 2, comprising 0 to 0.1% by weight dissolved in physiological saline.