【Abstract】 Objective To explore the clinical application and outcomes of preoperative second measurement of three-dimensional (3-D) CT reconstruction data for scoliosis orthopedic surgery. Methods Between August 2006 and March 2008, 11 patients with severe rigid scoliosis received surgery treatment, including 4 males and 7 females with an average age of 17.2 years (range, 15-19 years). Preoperative second measurement of 3-D CT reconstruction data was conducted to guide the surgery， including the angle and width of pedicle, the entry point, and the choice of screws whose lengths and diameters were suitable. A total of 197 pedicle screws were implanted. The operation time， blood loss， postoperative nerve function，and Cobb’s angles at sagittal and coronal view were all recorded， and the postoperative CT scan was performed to assess the accuracy of pedicle screw insertion according to Andrew classification. Results Pedicle screws were implanted within 1-11 minutes (mean, 5.8 minutes), and the blood loss was 450-2 300 mL (mean, 1 520 mL). The postoperative X-ray films showed the correction rates of Cobb’s angle were 68.5% in coronal view and 55.5% in sagittal view. The accuracy of pedicle screw insertion was rated as grade I in 77 screws (39.1%)，grade II in 116 screws (58.9%)， and grade III in 4 screws (2.0%) according to postoperative CT scan. All 11 cases were followed up 14 months to 2 years without any complications. Conclusion Preoperative second measurement of 3-D CT reconstruction data can make the surgery process easy and accurate in treatment of severe scoliosis.
