Patients with rheumatic diseases receiving GCs (≧0.5 mg/kg/day for prednisolone equivalent) within the past 2 months were enrolled in this study, and treated with 200 mg/day of etidronate cyclically. The bone mineral density (BMD) of lumbar spines (L2-4) was examined by QDR2000. OFH was evaluated by magnetic resonance imaging (MRI). ClinicalTrials.gov identifier: NCT00679978.