We experienced traumatic myositis ossificans affecting triceps on the left elbow in a 17-year-old boy. His elbow joint was dislocated by a fall in Judo. After one week, he was treated by over-vigorous massage and passive stretching. Ectopic calcification and ossification were induced on his elbow three months after dislocation, and he visited our hospital. To this patient, we administered 1000mg EHDP (Disodium ethane-1-hydroxy-1, 1-diphosphonate) for two months and 600mg EHDP for next one month. During the treatment his elbow joint motion was gradually improved, and serial X-rays showed a resolution of ectopic calcification. He showed no side effects during and after EHDP administration.
