Abstract:[Objective] To compare the clinical outcomes of pedicle screw placement at the injured vertebra after and before fracture reduction in posterior short-segment fixation for Magerl type A3 thoracolumbar fractures. [Methods] From December 2018 to June 2020, 59 patients who were undergoing surgical treatment for Magerl type A3 thoracolumbar fractures were randomly divided into two groups. All the patients received posterior short-segment fixation with the intermediate screws. Of them, 32 patients had the screws at injured vertebra placed after fracture reduction by using self-developed reducing rods with the upper and lower pedicle screws (the reduced group), while the remaining 27 patients had the screws placed before fracture reduction as usual (the conventional group). The documents regarding to perioperative period, follow-up and radiographs were compared between the two groups. [Results] All patients in both groups had surgical procedures completed successfully without serious intraoperative complications. There was no statistically significant difference between the two groups in terms of operation time, intraoperative blood loss, incision length, hospital stay, the time to return walking and the time to resume full-weight bearing activity (P>0.05) . All the 59 patients were followed up for 12-21 months with an average of (14.42±2.04) months. Both the VAS score and the ODI score decreased significantly in both groups over time (P<0.05) , however, no significant differ- ence was noted in the two scores at any corresponding time point between the two groups (P>0.05) . Regarding to radiographic assessment, the relative anterior vertebral height, kyphotic Cobb angle and spinal canal occupation ratio significantly improved postoperatively com- pared with those before operation in both groups (P<0.05) . Although there was no statistically significant difference in the relative anterior vertebral height and kyphotic Cobb angle at any matching time point (P>0.05) , the reduced group proved significantly superior to the con- ventional group in term of spinal canal occupation ratio at 3 days after operation and the latest follow- up (P<0.05) . [Conclusion] Both short-segment pedicle screw fixation with screws placement at the injured vertebra after or before fracture reduction achieve satisfactory and comparable clinical outcomes for Magerl type A3 thoracolumbar fractures. However, the screws placed after fracture reduction does im- prove spinal canal occupation better.