Corrective osteotomy for cervicothoracic deformity secondary to ankylosing spondylitis / 中华骨科杂志

ABSTRACT

Objective To report the application of C7T1extensive osteotomy and C7pedicle subtraction osteotomy(PSO) in the correction of cervicothoracic deformity secondary to ankylosing spondylitis(AS)and to investigate the efficacy and safety of the techniques.Methods Between April 2006 and August 2017,eight male patients with cervicothoracic deformity undergoing C7T1extensive osteotomy(3 cases)or C7PSO(5 cases)were retrospectively reviewed.The mean age was 31.3±14.9 years(range, 14-60 years).C2-T1kyphosis,C2-T1scoliosis and C2-T1sagittal vertical axis(SVA)were measured on the lateral cervical radio-graphs and chin-brow vertical angle(CBVA)was measured on clinical photographs preoperatively and at the final follow-up.The operative time, blood loss and complications were recorded. Results The average follow-up duration was (11.3 ± 7.9) months (range,3-48 months).In C7T1extensive osteotomy group,the mean operative time was 305 min(300-310 min)and the average blood loss was 1 250 ml(1 000-1 500 ml).Preoperative and postoperative C2-T1kyphosis were 17.0°±16.3°and-13.3°±20.2°,re-spectively.The preoperative CBVA was 20.0°±4.5°,which improved to 4.7°±5.9°at the final follow-up with a mean correction rate of 76.5%.C2-T1SVA was improved from(6.9±4.0)cm preoperatively to(3.5±1.8)cm at the final follow-up with an average correc-tion rate of 49.3%.In C7PSO group,the mean operative time was 536 min(375-730 min)and the average blood loss was 2 450 ml (700-4 200 ml).There were four patients with concomitant scoliosis and kyphosis.Preoperative and postoperative C2-T1kyphosis were 22.8°±10.5°and-13.5°±10.0°,respectively.The preoperative C2-T1scoliosis was 24.8°±12.7°,which improved to 5.0°±3.5° at the final follow-up with a mean correction rate of 79.8%.CBVA was improved from 60.5°±10.2°preoperatively to 14.3°±8.6°at the final follow-up with an average correction rate of 76.4%.C2-T1SVA was corrected to(6.4±2.5)cm at the final follow-up from(10.4 ± 4.3) cm preoperatively. One patient was presented with severe cervicothoracic scoliosis and the C2-T1scoliosis was im-proved to 10°from 33°with a 69.7% correction rate.No neurological complications,infection,or implant-related complications were observed both intraoperatively and during the follow-up period.One patient who underwent C7PSO experienced intraopera-tive subluxation of the osteomized vertebra.Fortunately,there was no neurological deficit.Solid bony fusion was observed after six-month Halo-vest immobilization.Conclusion Both C7T1extensive osteotomy and C7PSO are effective in the correction of cervico-thoracic deformity secondary to AS with acceptable complication rate.C7PSO is particularly suitable for the correction of severe and complicated biplanar cervicothoracic deformity.