Comparison of graduation results of early onset scoliosis patientsand posterior instrumentation and fusion results of adolescent idiopathic scoliosis patients between paired groups

Early-onset scoliosis (EOS) is a progressive, life-threatening condition that needs to be treated carefully. Treatment with growing rods (GR) is the most frequently preferred method, and is usually followed by posterior instrumentation and fusion (PIF), which is also called graduation. Graduation surgery is technically demanding and complicated, leading to a preference for avoiding definitive fusion when there's adequate improvement in scoliosis angle, no implant failure, and no need to change instrumentation level. To compare the risks and benefits of instrumented posterior fusion between patients with adolescent idiopathic scoliosis (AIS) treated with standard PIF, and patients with idiopathic EOS treated with GR and graduated with PIF. This is a retrospective study. The study included patients with idiopathic etiology EOS who underwent dual-GR and definitive surgery, as well as those who underwent standard PIF with AIS diagnosis during the study period. The AIS and the EOS groups were matched in terms of coronal deformity (scoliosis angle), sagittal deformity (T2- T12 kyphosis, L1-S1 lordosis), gender, and age variables by Propensity Score Matching analysis (Method nearest 1:3). Seven hundreds seventy-six patients (24 EOS, 752 AIS) were included in the study. Seventy-two AIS patients were matched against 24 EOS patients. Significant differences were found between the groups in terms of scoliosis correction percentage, surgery time, transfusion need, and number of instrumented segments. The percentage of T1-T12 increase, percentage of T1-S1 increase, instrumented spinal segment length increase, and the estimated of blood loss (EBL) were similar. Complications were seen in five patients (20.8%) in the EOS group. One patient experienced intraoperative neuromonitoring alerts, which resolved with appropriate intervention. One superior mesenteric artery syndrome, two proximal anchor loosening and one superficial infection were recorded. Five patients (6.8%) in the AIS group had complications (two screw malposition, one shoulder imbalance, one trunk shift, one adding-on) and required revision surgery. Although the EOS group had longer surgical time, more bleeding, and less correction of the coronal deformity, trunk height gained by definitive surgery was the same as the AIS group. There is a difference in favor of AIS between the groups in terms of coronal deformity correction rates, but the final scoliosis angle of EOS patients is clinically satisfactory [(22.17 ±13.07°)]. In conclusion, definitive fusion in EOS with idiopathic etiology does not carry an excessive risk for complications, and the gains obtained by the patients at the end of surgery are remarkable.