Loading rate-dependent property of different layers for articular cartilage / 医用生物力学

ABSTRACT

Objective To investigate the loading rate-dependent property of different layers for articular cartilage by unconfined compression testing on articular cartilage at different loading rates. Methods The non-contact digital image correlation (DIC) technique was applied to investigate the mechanical properties of different layers for fresh pig articular cartilage at different loading rates. Results At constant loading rate, the compressive strain of superficial layer and deep layer was the largest, while that of middle layer was in between under the same compressive stress. The Poisson’s ratio increased from superficial layer to deep layer along with cartilage depth increasing. The stress-strain curves of cartilage were different at different loading rates, indicating that the mechanical properties of cartilage were dependent on the loading rate. The elastic modulus of cartilage increased with loading rates increasing, and the compressive strains of different layers decreased under the same compressive stress with loading rates increasing. Conclusions The compressive strain decreased while the Poisson’s ratio increased from superficial layer to deep layer along the cartilage depth. The mechanical properties of different layers for cartilage were dependent on the loading rate. This study can provide the basis for clinical cartilage disease prevention and treatment, and is important for mechanical function evaluation of artificial cartilage as well.