抄録
The purpose of this study was to investigate the relationship between mechanical properties and passive electrical property for articular cartilage. In the present study, the magnitude of admittance IYI was used to evaluate passive electrical property. Cartilage specimens without subchondral bone were taken from porcine knee joints with biopsy punch with 6 mm diameter. The specimen of 1.2 mm thickness was firstly prepared and its magnitude of admittance IY1 was measured. This specimen was then sliced from 1.2 mm to 0.9 mm thickness and then again from 0.9 mm to 0.6 mm, and its magnitude of admittance I11 was measured at each thickness. The magnitude of admittance IYI for the specimen of 1.2 mm thickness was measured under 20 and 40 °C. The magnitude of admittance III is constant at high frequencies and variation of the saturated value with thickness and temperature of the specimen were observed at high frequencies. These results showed that passive electrical property of cartilage can be evaluated by the magnitude of admittance III at high frequencies. Electric impedance measurement and stress-relaxation test were carried out for the same specimens of 1.2 mm thickness to evaluate relationship between the passive electrical property and mechanical properties obtained using three elements model. The magnitude of admittance 1/1 showed a significant negative correlations with elastic modulus El(r = -0.704, P<0.05), elastic modulus E2(r = -0.704, P<0.05), and viscosity coefficient ri(r = -0.689, P<0.05) respectively. These results showed that mechanical property of articular cartilage can be estimated by using an electric impedance method.
