ABSTRACT
Myositis ossificans is metaplasia of mesenchymal tissue with bone formation.The process of myositis ossificans is analogous to the cell changes that occur at sites of fracture healing (p. 55). In the callus formed around a fracture, fibroblasts and osteoblasts are indistinguishable and are differentiated by the nature of the nearby extracellular matrix that they synthesise.The fibroblasts and osteoblasts have separate identities but come from the same stem cell. Their varied behaviour
explains the complex cellular response seen in myositis ossificans.
