VISCOELASTIC PROPERTIES OF THE HUMAN SEMILUNAR CARTILAGE

We performed the experiment to observe the mechanical and physical properties of the semilunar cartilage in the knee of the pig and the human, which were preserved in silicone oil at 4°C for four days. The experiments were all performed in silicone oil and within an hour at room temperature. The observed stress-strain curve for pig menisci was sigmoid and this was proved to be due to its net-like framework of collagenous fibres by wide angle X-ray diffraction and stress relaxation experiments. Young's modulus was calculated from the linear part of stress-strain curve showing 1.75 × 108 dyn/cm2 with 1.7%/sec strain rate. The strain rate dependency of Young's modulus increased very slightly. This is contrary to the suggested idea that the meniscus could mainly play a role of a shock absorber in the knee joint. Stress relaxation tests with tensile load revealed no difference in visco-elastic properties between human normal and torn menisci. © 1979.