Sequential correction using satellite rod for severe thoracic idiopathic scoliosis: an effective method to optimize deformity correction

Abstract

OBJECTIVE The aim of this paper was to compare the radiographic and clinical outcomes between the sequential correction (SC) technique and the traditional 2-rod correction (TC) technique in patients with severe thoracic idiopathic scoliosis (STIS) undergoing posterior-only correction surgery. METHODS Records of a consecutive series of STIS patients undergoing posterior-only correction surgery between October 2013 and October 2017 with more than 2 years of follow-up were reviewed. The radiographic parameters were assessed preoperatively, postoperatively, and at the last follow-up. Radiographic parameters, operative time, blood loss, and complications were compared between the two groups. RESULTS A total of 33 patients were included in the SC group, and 21 patients were included in the TC group. There was no significant difference in age, sex, or deformity magnitude (93.6° ± 7.8° vs 89.8° ± 6.6°, p = 0.070) preoperatively between groups. The operation time was shorter in the SC group than in the TC group (251.5 ± 42.8 minutes vs 275.4 ± 39.8 minutes, p = 0.020), while both blood loss (1284.6 ± 483.3 vs 1398.0 ± 558.4 ml, p = 0.432) and number of fused levels (13.1 ± 2.8 vs 13.6 ± 2.4, p = 0.503) were similar between the groups. Compared with the TC group, patients in the SC group had a higher correction rate (55.8% ± 9.2% vs 45.7% ± 8.8%, p < 0.001), less coronal (1.1° ± 0.81° vs 2.9° ± 0.93°, p < 0.001) and sagittal (1.5° ± 0.96° vs 2.1° ± 0.64°, p = 0.015) correction loss at the 2-year follow-up, and a lower incidence of intraoperative pedicle screw pullout (14.3% vs 23.8%, p = 0.026). CONCLUSIONS The SC technique could significantly and practically reduce the difficulty of rod installation with better deformity correction outcomes than the traditional TC technique. The SC technique was an effective alternative for patients with STIS.