A long-term follow-up study of thirty-seven cases of polyostotic fibrous dysplasia and thirteen cases of monostotic fibrous dysplasia is presented. In three fatalities, death could probably be attributed to polyostotic involvement. In two other patients, sarcoma developed after radiation of a lesion. The criteria for the diagnosis of fibrous dysplasia are discussed. The evolution of the skeletal lesions was studied by serial roentgenograms. The appearance of new lesions and enlargement of pre-existing ones after puberty was not uncommon.
Repeated biopsies showed essentially no maturation of the fiber-bone trabeculae or of the fibrous tissue. Cartilage islands were present in only 14 per cent of patients with polyostotic fibrous dysplasia and in none of the patients with monostotic fibrous dysplasia.
Recommendations for therapy are made on the basis of an evaluation of the results of repair of 125 fractures and fifty-one operative procedures in the thirty-seven cases of polyostotic fibrous dysplasia.