Polarized light microscopy technique for imaging articular cartilage

Polarized light microscopy (PLM) is a useful microscopic imaging technique that can generate contrast in birefringent specimens and determine qualitative and quantitative aspects of crystallographic axes present in various materials such as glass, plastic, and optical fibers. In biomedical research, PLM is the gold standard imaging technique for the collagen ultra-structure in tissues such as cartilages and tendons. The technique uses a physical property of the collagen fibers, namely the birefringence, to indirectly describe the morphological features of the collagen fibers in cartilage. In this paper, we describe a PLM technique that can be used to find the collagen-fiber orientation and to construct histological zonal imagining for the superficial, transitional and radial zones in articular cartilages.