MYOSITIS OSSIFICANS PROGRESSIVA

¹ The Department of Pediatrics, Vanderbilt University School of Medicine, Nashville.

Four new cases of myositis ossificans progressiva have been presented and the literature on the subject has been reviewed.

At the onset typical cases will usually develop palpable masses over the fascial planes of the head and neck. Biopsy of these lesions suggests tumor tissue but this subsequently goes on to calcification and ossification.

This point illustrates that the disease title—myositis ossificans—is really a misnomer since there is no calcification of muscles themselves but rather a calcification of the connective tissue between the muscles.

When the disease progresses as illustrated by the cases reported, they frequently present themselves with gait or posture disturbance or with other orthopedic complaints. Microdactylism and hallux valgus deformity of the great toe are two of the outstanding findings.

The cases reported illustrate the various stages of the disease under discussion. From inflammation, swelling, induration of the muscles and connective tissues to tumefaction, the disease finally progresses to calcification in from 2 to 8 months. Finally, the calcification progresses to ossification and severe crippling. Serial illustrations and roentgenograms on several of these cases illustrate these progressive changes.

All biochemical determinations have been normal but marked subjective improvement following cortisone therapy in one early case suggests the possible relationship of this disease process to disturbed steroid metabolism.