STUDY DESIGN: A retrospective study. OBJECTIVES: To assess the efficiency of undercorrection and transpedicular screw fixation through a posterior approach in osteoporotic spine fractures with a thoracolumbar kyphotic deformity. SUMMARY OF LITERATURE REVIEW: The surgical treatment of osteoporotic spine fractures with a thoracolumbar kyphotic deformity requires extensive surgical procedures to obtain complete restoration of the sagittal alignment, but it has a few technical limitations due to insufficient mechanical stability at the bone-screw interface. A special strategy is essential for transpedicular screw fixation for osteoporotic spine fractures with a thoracolumbar kyphotic deformity. MATERIALS AND METHODS: We reviewed 14 osteoporotic spine fracture cases, with a thoracolumbar kyphotic deformity, which had undergone undercorrection and transpedicular screw fixation through a posterior approach, between March 2000 and June 2003, with an average follow-up period of 15. 2 months. According to the Jikei grade of the osteoporosis, 9 and 5 cases were grades 2 and 3, respectively. As a radiographic assessment, we measured the kyphotic angles of the fused segments on the preoperative, postoperative and last follow up thoracolumbar lateral views on standing using Cobb's method, and also assessed the kyphotic angle correction (KAC). The clinical results were evaluated at the last follow-up. RESULTS: The kyphotic angles at the preoperative, postoperative and last follow-up were 33.5 degrees +/- 9.3, 22.4 degrees +/- 6.9 and 24.7 degrees +/- 6.8, respectively. We obtained a mean KAC gain of 11.1 degrees postoperatively (p<0.05), but a loss of 2.3 degrees at the last follow-up (p>0.05). The clinical results were analyzed as good, fair and poor in 8, 5 and 1 case, respectively. Fusions were achieved in all cases. CONCLUSIONS: Undercorrection and transpedicular screw fixation for a thoracolumbar kyphotic deformity in osteoporotic spine fractures can be one of the alternatives to avoid fixation failure and an extensive surgical procedure.