Androgens have proliferative effects on osteoblasts and increase fracture healing by systemic and local stimulation of bone formation. The aim of the present study was to evaluate if the systemic stimulation by androgens leads to increased bone-defect healing. Ten mature, healthy, white Newzealand rabbits were selected and all rabbits were castrated with scrotal approach. The rabbits were divided into two groups. After general anesthesia, a hole in size of 1×4 mm in diameter and depth was created in the middle of the left tibia shaft with low speed dental bit. Group 1 (5 rabbits) were injected with nandrolone 2 mg/kg body weight intramuscularly. Group 2 the 5 control rabbits received cyproterone acetate 5 mg/kg body weight orally. 50 days after surgery, the rabbits become Euthanasia. Then bone defect was evaluated by means of histomorphometrical factor. Histomorphometrical evaluation showed that the percentage of bone formation in group 1 was equivalent to 54.30±0.28 which was higher among other group. The results show that androgenic steroid such as nandrolone can increase the bone healing in middle shaft of tibia defect in rabbit.
