1. Normal hyaline cartilage contains glycogen in all its cells, with the exception of time peripheral growth zones and the tangential layer of the articular cartilage.
2. In growing epiphyseal cartilage the behavior of glycogen differs according to the rate of growth. The increase of glycogen is constant in hypertrophic cartilage; however, it disappears completely it growth is fast, partially if growth is moderate, or remains if growth is slow.
3. Glycogen is usually scarce in areas of primary bone trabeculae in the subchondral layer of endochondral ossification, except in parts where growth is slow and glycogen is found in moderate quantities.
4. Glycogen is constantly present in direct or membranous ossification; its distribution varies according to the speed of osteogenesis.
5. In areas of active osteogenesis, the hypertrophic osteoblasts contain little or no glycogen, while the adjacent mesenchymal cells (pre-osteoblasts) contain a moderate to abundant quantity of glycogen granules. The flattened atrophic osteoblasts on the surface of slowly growing bone trabecubae contain abundant glycogen. The osteocytes in both of these conditions usually lack glycogen.
Copyright 1958 by The Journal of Bone and Joint Surgery, Incorporated