Comprehensive verification on Mechanical Diagnosis of Osteoarthritic Cartilage using Dynamic Optical Coherence Straingraphy

Abstract

Many of the elderly are predisposed to develop osteoarthritis (OA), although it is quite difficult to diagnose the early-grade OA even by latest imaging modalities. In this study, we have proposed Dynamic Mechanical Analyzing Optical Coherence Straingraphy, namely DMA-OCSA, which is a tomographically micro-visualizing method of visco-elastic properties estimated from continuous OCT images. This is based on the speckle tracking algorithm having high sensitivity and S/N under micrometer resolution, thus can provide temporal and spatial distribution of not only deformation velocity but also strain rate during a dynamic visco-elasticity test. This was experimentally applied to comparatively Osteoarthritic cartilage of animal models. Consequently, the sinusoidal time-varying strain rate was locally observed to have phase difference between the superficial tangential zone and middle zone, which could cause degradation of visco-elasticity.