The purpose was to compare tibial bone union in normal and osteopenic female rats. Forty-nine Wistar albino female rats weighing 160 g (±20g) and 100 days were distributed into 2 groups: Oophorectomized (OOF) and Pseudo-oophorectomized (SHAM). Thirty days later, a cortical injury was produced in all the animals. They were sacrificed in the 2nd, 4th, 6th and 8th weeks. Osteoblasts count was performed. Progressive weight increase was observed, but the OOF group was shown to have gained more weight (p£0.05) than the SHAM group, at the time of the second surgery. After 15 days post-injury, the animals in the OOF group presented a higher number of osteoblasts (p£0.05) compared to the SHAM group. Thirty days after injury, the number of osteoblasts was reduced, but both groups showed similar amounts. Forty-five days after injury, despite a constant reduction, the number of osteoblasts in the OOF group remained high when compared to SHAM (p£0.05) group. After 60 days, we found less osteoblasts in the SHAM group, suggesting an advanced bone repair process. The osteopenic animals showed an early accelerated response, which became equivalent between both groups 30 days after injury. However, after that period, they showed a delayed osteoid mineralization, suggesting delayed late bone repair process.
Osteoporosis; Ovariectomy; Osteopenia
