Disodium etidronate in the prevention of postoperative recurrence of heterotopic ossification in spinal-cord injury patients.

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.