Disodium etidronate was used in a clinical trial with four patients to
study its effectiveness in preventing the recurrence of mineralization
after surgical removal of heterotopic ossification. These patients, who had
sustained injuries to the spinal cord followed by anklysos of the hip, had
seven surgical wedge resections as part of a controlled or double-blind
study. Roentgenograms showed that in the resections done without the drug
there was recurrence within three weeks, whereas with the drug there was no
sign of recurrence as long as the drug was administered. After
discontinuation of drug therapy, recurrence was variable but less than
expected. Disodium etidronate is the first therapeutic agent which may
delay and partially prevent postoperative recurrence of heterotopic
ossification.