Objectives:To investigate the clinical efficacy and safety of posterior reduction and fixations in patients with thoracolumbar burst fractures with Load-sharing classification(LSC)score of 7 and 8 points.Methods:The data of 36 patients with LSC score of 7 and 8 who underwent posterior reduction and internal fixation between October 2009 and December 2014 were retrospectively analyzed.There were 21 males and 15 females,with an average age of 42.67±14.67 years(range 21 to 67 years).The fractured vertebrae were T12-Ll.LSC score was graded according to the imaging data including X-ray radiographs,CT and MRI.The index vertebral Cobb angle and anterior vertebral height were collected at preoperative,postoperative 1 week and final follow-up,respectively.Visual analogue scale(VAS)was used to evaluate residual back pain at final follow-up.The complications were recorded for safety evaluation.Results:All the patients were followed up for 49.83±18.20 months on average(23-86 months),of which 19 cases had internal fixations removed,and the follow-up period for patients after internal fixation removal was 28.00±20.12 months on average(3-69 months).Fracture healing was achieved in all the patients without significant residual pain,or broken screw or rod,or significant kyphosis,or pedicle screw cutting vertebral body or loosening of the internal fixation.For imaging evaluation,the postoperative sagittal Cobb angle was significantly improved to 6.67°±5.06° from the preoperative 15.87°±8.35°,and the postoperative height of anterior margin of the fractured vertebral body recovered to 2.88±0.32cm from 1.81±0.49cm before operation,all with statistically significant differences(P＜0.05).The vertebral body height at the final follow-up was 2.81±0.41cm,and there was no statistically significant difference between postoperative and the final follow-up vertebral body heights(P＞0.05).At the final follow-up,the neurological functions of all the patients recovered compared with the conditions at the time of injury,with no loss of intervertebral space height.The anterior edge height of the vertebral body recovered to(94.92±18.41)％,the middle edge height recovered to(81.16±11.82)％,and the posterior edge height recovered to(97.48±7.63)％,all with significant differences compared to those before surgery(P＜0.05).Conclusions:The posterior reduction and internal fixation for patients with thoracolumbar burst fracture with LSC scores of 7 and 8 can achieve good preservation of vertebral stability at later stage,high safety,and satisfactory clinical efficacy and imaging results.