Formation of long bones on the basis of a cartilaginous model. Longitudinal growth takes place both in growth plates and in the articular cartilage. At the growth plates, chondral ossification takes place. Cartilage cells calcify, serving as a basis for bone formation, and bone is deposited; cartilage is then replaced by bone.
The formation of bone in cartilage, as in the formation of long bones, involving the destruction and removal of cartilage and the formation of osseous tissue in the space formerly occupied by the cartilage.