Ponte osteotomy followed by sequential correction technique with satellite rods in severe rigid thoracic scoliosis

Objective To investigate the efficacy and safety of Ponte osteotomy and sequential correction technique with satellite rod construction in the treatment of severe rigid thoracic scoliosis. Methods A total of 32 patients (12 male, 20 female) with severe rigid thoracic scoliosis (Cobb angle>100°) who underwent posterior Ponte osteotomy and sequential correction technique with satellite rod construction between October 2012 and October 2016 and with more than 2 years follow-up were retrospectively reviewed. Major curve Cobb angle, apex vertebral translation, trunk shift, thoracic kyphosis and lumbar lordosis were measured through standing posterior-anterior X-ray preoperatively, postoperatively and at the final follow-up. The duration of operation, blood loss and complications were recorded. SRS-22 questionnaire was used to evaluate the clinical outcomes. Results The average age was 21.3±10.8 years (range from 17 to 46 years). The mean preoperative major curve Cobb angle was 117.8°±9.8°(range from 104° to 131°) with a mean flexibility of 13.9% and the mean thoracic kyphosis was 65.5°±18.7° (range from 48° to 87°). The mean duration of operation was 267.4±42.3 min and the mean blood loss was 895.4±103.1 ml. The mean fused levels ranged from T2 to L4 with a mean 13.3±2.4 fused segments. The mean implant density was 62.1%±8.8%. Ponte osteotomy was performed in 4-9 segments which was 6.1±1.9 segments in average. The coronal main curve was corrected to 54.4°±10.9° with a mean correction rate of 53.9%±9.3% and the mean thoracic kyphosis was corrected to 35.6°±12.0°, which were both significantly improved. The average follow-up time was 34.3±8.9 months. At the last follow-up, the mean coronal main curve was 53.1°±1.9° with a mean correction loss of 1.3° and the thoracic kyphosis was 36.7°±11.4°. There were no neurological deficit or implant failure postoperatively and follow-up. Conclusion Ponte osteotomy followed by sequential correction technique with satellite rods construction was safe and effective which could achieve satisfactory correction rate and less correction loss during the longitudinal follow-up in the treatment of severe rigid thoracic scoliosis. Key words: Thoracic vertebrae; Scoliosis; Osteotomy; Orthopedic procedures