The object of this study was to examine the efficacy of preoperative teriparatide treatment for increasing the insertional torque of pediclescrews during fusion surgery in postmenopausal women with osteoporosis. Fusion surgery for the thoracic and/or lumbar spine was performed in 29 postmenopausal women with osteoporosis aged 65-82 years (mean 72.2 years). The patients were divided into 2 groups based on whether they were treated with teriparatide (n = 13) or not (n = 16) before thesurgery. In the teriparatide-treated group, patients received preoperative teriparatide therapy as either a daily (20 μg/day, n = 7) or a weekly (56.5 μg/week, n = 6) injection for a mean of 61.4 days and a minimum of 31 days. During surgery, the insertional torque was measured in 212 screwsinserted from T-7 to L-5 and compared between the 2 groups. The correlation between the insertional torque and the duration of preoperativeteriparatide treatment was also investigated.