Figure 1: Ovariectomized bone defect animal model. (a) Schematic representation of the drill-hole defect area using micro-CT analysis. The drill-hole is located in the lateral plane of the tibial plateau. The diameter of the tibial drill-hole was 1.5 mm, which penetrated one side of the bone cortex. (b) Bone mass densities of rats before and after ovariectomy (, postovariectomy versus preovariectomy).