Myositis ossificans traumatica is the most frequently used term under which several more or less similar lesions are described. This name is widely used in the literature to designate a condition, not including ordinary callus, associated with the reaction of certain tissues to trauma. The structures involved may include the bone itself, the periosteum, the muscle and its fascial sheaths or the tendinous attachment of muscle to bone. Other names are used to indicate these abnormal bony masses: exostosis, myositis ossificans circumscripta and aberrant exostosis. Another condition bears a strong relation to this group and is sometimes included with it; the occasional formation in scar of bony tissue, especially after operation on the urinary bladder and in the upper part of the abdominal wall.
Ossifying hematoma is usually included in this group also, but this term is not widely used. In this condition the periosteum is believed to be stripped