Objective To explore the failure cause of posterior approach orthopaedic operation of thoracolumbar hemivertebra, and to summary strategies of revision. Methods The cl inical data from 9 cases undergoing posterior approach orthopaedic operation failure of thoracolumbar hemivertebra between June 2003 and June 2008, were retrospectively analyzed. There were 5 males and 4 females with a median age of 12 years (range, 1 year and 10 months to 24 years). All malformations were identified as fully segmented hemivertebra from the original medical records and X-ray films, including 2 cases in thoracic vertebra, 5 cases in thoracolumbar vertebra, and 2 cases in lumbar vertebra. The preoperative scol iotic Cobb angle was (45.4 ± 17.4)°, and kyphotic Cobb angle was (29.8 ± 22.0)°. The reason of primary surgical failure were analyzed and spinal deformity was corrected again with posterior revision. Results All surgeries were finished successfully. The operation time was 3.0-6.5 hours (mean, 4.5 hours), and the perioperative bleeding was 400-2 500 mL (mean, 950 mL). All incisions healed by first intention; no infection or deep venous thrombosis occurred. Numbness occurred in unilateral lower extremity of 1 case postoperatively, and the symptom was rel ieved completely after treatment of detumescence and neural nutrition. All cases were followed up 12-30 months (mean, 18 months). No pseudoarthrosis and implant failure occurred. The X-ray films showed that the bone grafts completely fused within 8-14 months (mean, 11 months) after operation. The Cobb angles of scol iosis and kyphosis at 1 week after operation and the last follow-up were obviously improved when compared with preoperative ones, showing significant differences (P lt; 0.05). No obvious correction loss was observed either in coronal or sagittal plane. Conclusion The failure causes of posterior approach orthopaedic operation are hemivertebra processing, selection of fixation and fusion range, and selection of internal fixation. If the strategies of revision are made after the above-mentioned failure causes are considered, the cl inical results will be satisfactory.