Fig. 3From: Basic science of osteoarthritisOrganization of the normal adult articular cartilage. a Organization of the chondrocytes in their ECM in superficial, middle, and deep zones. The cement line separates the calcified zone from the subchondral bone. Major ECM components are presented in the box. b Normal PCM and cell-matrix interface (adapted from Heinegård & Saxne 2011)Back to article page