Fracture healing in rats treated with diphenylhydantoin (Dilantin).

Fibula fractures were surgically made in mature male rats. Experimental animals received 4 mg/kg body weight of DPH (Dilantin) injected intraperitoneally, and equivalent volumes of sterile saline were injected intraperitoneally in controls. Fracture healing was assessed by a histologic method 5, 10, 15, 20, 25, and 30 days following the fracture. Thirty days following the injury, the DPH-treated animals showed a statistically significant increased rate of union. A comparison in trends of fracture healing for experimental and control animals showed similar enhancement of fracture healing in the experimental animals throughout the entire observation period.