Effect of ifosfamide on bone healing.

The effect of ifosfamide on bone healing was tested in a controlled experiment of fibular osteotomy in immature rabbits. Standardized shaft osteotomy was implemented in 10 experimental subjects (group 2) and 10 controls (group 1). Experimental animals received a 50 mg/kg ifosfamide dose by intraperitoneal injection on the fourth post-operative day, and for five days thereafter, while controls received injections of distilled water. After five weeks, all animals were submitted to pharmacological euthanasia and the resulting bone callus samples were studied with histomorphometry, using hematoxylin-eosin stain. Group 2 presented smaller bone volume (69.03% versus 84.98%), larger fibrosis volume (30.96% versus 15.02%), and larger resorption surface (22.02% versus 16.17%) than group 1 (all p< or = 0.05). We conclude that ifosfamide is able to alter the physiological bone healing process by producing a less mature callus (characterized by a smaller quantity of bone tissue), a larger quantity of fibrous tissue, and a smaller resorption surface.