Figure 1

Zonal organization of articular cartilage (longitudinal view). (A) Hematoxylin and eosin staining section shows the chondrocytes and extracellular matrix distribution in articular cartilage. (B) Safranin O staining section shows that proteoglycan distribution increases from superficial zone to deep zone. (C) A schematic image of an aggrecan aggregate. (D) The schematic diagram represents the arrangements of collagen and elastin fibers within articular cartilage and changes in chondrocyte shape and arrangement with depth.