Posterior three-column osteotomy for the treatment of congenital thoracolumbar kyphosis: a comparison of long and short segment instrumentation

English Keywords:Congenital abnormalities  Kyphosis  Osteotomy  Distal fusion level

English Abstract:

  【Abstract】 Objectives: To compare the clinical outcomes of long and short segment fixation following three-column osteotomies for congenital kyphosis(CK) in thoracolumbar spine. Methods: From January 2014 to December 2018, a consecutive cohort of 26 patients with kyphotic Cobb angle ranging from 50° to 80° who were treated with three-column osteotomies and pedicle screw fixation were retrospectively reviewed. 13 males and 13 females with a mean age of 11.5±4.5 years(range, 3-18 years) were included. According to the distal fusion level, the patients were divided into 2 groups. Long segment fixation group(n=12), included patients whose lowest instrumented vertebra(LIV) was 3 levels below osteotomy level; Short segment fixation group(n=14), included patients whose LIV was 2 levels below osteotomy level. There were no significant differences between the two groups in terms of age, sex, osteotomy technique, or osteotomy level(P>0.05). The patients were followed up for 37.1±10.3 months(24-81 months). On standing whole-spine X-rays preoperatively, 1 week postoperatively and at final follow-up, global kyphosis(GK), lumbar lordosis(LL), sagittal vertical axis(SVA), pelvic incidence(PI), pelvic tilt(PT), and sacral slope(SS) were measured. Intraoperative and postoperative complications were recorded. The Scoliosis Research Society-22 questionnaire(SRS-22) score was recorded at pre-operation and final follow-up to evaluate the clinical outcomes. Results: All surgeries were successfully completed. There were no significant differences in GK, LL, and SVA between the two groups preoperatively, postoperatively, and at the final follow-up(P>0.05). All three parameters showed significant improvement after surgery(P<0.05), and remained stable at the final follow-up(P>0.05). There were no significant differences in PI, PT, and SS between the two groups at any time point(P>0.05), and these parameters remained stable postoperatively(P>0.05). Intraoperative neurophysiological monitoring showed that one patient in each group had abnormal evoked potentials during osteotomy, while no neurological defect was observed during follow-up. There were no implant-related complications during follow-up. No significant difference was observed between groups in SRS-22 scores preoperatively(P>0.05). At the final follow-up, the function score(4.3±0.6) and pain score(4.3±0.4) of SRS-22 in short segment fixation group were significantly higher than those in long segment fixation group(3.8±0.7 and 3.8±0.6)(P<0.05). There was no significant difference in the rest of the domain(P>0.05). Conclusions: For CK patients with a cobb angle of 50°-80°, both long and short segment fixation after three-column osteotomies can effectively achieve satisfying curve correction, while short segment fixation could improve patients′ quality of life.