Heterotopic bone formation following trauma has been frequently reported. Myositis ossificans traumatica most often follows severe blows or is incident to repeated minor trauma primarily to the extremities. Football players and others engaged in contact type activities are particularly prone to develop this lesion. It is occasionally seen after severe sprains or may develop in areas of localized infection. Recently a few such ossifications have been observed in abdominal scars, and 16 were reported up to 1960.3,7 All were in men and all appeared within a year following operation. The original incisions were longitudinal and 14 were in the upper abdomen. Only two were reported to have been attached to the xiphoid.
Two possible mechanisms for the production of bone in myositis ossificans traumatica have been proposed. The first suggests that particles of periosteum or perichondrium are torn loose and implanted in adjacent muscle or fascia, thus initiating osseous