Methods: Inclusion criteria: ≥5-level fusion, sagittal/coronal deformity, and minimum 2-year follow-up. Primary outcomes were the highest quartile of EBL (mL), operative time (minutes), and LOS (days). EBL was calculated based on the hemoglobin drop. Bivariate analysis and multivariable logistic regression were performed, controlling for age, comorbidities, and preoperative radiographic parameters. Results: Among 238 patients (mean age, 63.4±17.4 years), the highest EBL quartile (2,594.0±1,550.5 mL) had more three-column osteotomies (3CO) (30.5% vs. 14.8%, p=0.008). Multivariable predictors of highest EBL were older age (odds ratio [OR], 1.03; p=0.039) and 3CO (OR, 3.60; p=0.007). The highest operative time quartile (618.9±99.4 minutes) had more 3CO (27.1% vs. 15.3%, p=0.041) and higher rod fracture rates (30.5% vs. 15.8%, p=0.014). Multivariable predictors of the highest operative time were higher total instrumented levels (TIL) (OR, 1.26; p<0.001) and older age (OR, 1.05; p=0.003). The highest LOS quartile (14.5±18.5 days) had more 3CO (27.3% vs. 14.3%, p=0.045). The multivariable predictor of highest LOS was higher TIL (OR, 1.23; p<0.001). Conclusions Three-column osteotomy was the strongest predictor of perioperative morbidity in ASD surgery, consistently associated with higher blood loss, longer operative times, and prolonged hospital stays. Recognizing its impact can inform surgical strategies to improve patient outcomes.

Background/Aims: Patients of ulcerative colitis (UC) on follow-up are routinely evaluated by sigmoidoscopy. There is no prospective literature to support this practice. We assessed agreement between sigmoidoscopy and colonoscopy prospectively in patients with disease extent beyond the sigmoid colon. Methods: We conducted a prospective observational study at a tertiary care institute for agreement between sigmoidoscopy and colonoscopy. We assessed endoscopic activity using the Mayo Endoscopic Score (MES) and Ulcerative Colitis Endoscopic Index of Severity (UCEIS) and histological activity using the Nancy Index (NI), Robarts Histopathology Index (RHI), and Simplified Geboes Score (SGS). Results: Sigmoidoscopy showed a strong agreement with colonoscopy for MES and UCEIS with a kappa (κ) of 0.96 and 0.94 respectively. The misclassification rate for MES and UCEIS was 3% and 5% respectively. Sigmoidoscopy showed perfect agreement (κ = 1.00) with colonoscopy for assessment of the presence of endoscopic activity in the colon using MES ≥ 1 as activity criteria and strong agreement (κ = 0.93) using MES > 1 as activity criteria. Sigmoidoscopy showed strong agreement with colonoscopy for assessment of the presence of endoscopic activity using UCEIS (κ = 0.92). Strong agreement was observed between sigmoidoscopy and colonoscopy using NI (κ = 0.86), RHI (κ = 1.00), and SGS (κ = 0.92) for the detection of histological activity. The misclassification rate for the detection of histological activity was 2%, 0%, and 1% for NI, RHI, and SGS respectively. Conclusions Sigmoidoscopy showed strong agreement with colonoscopy for endoscopic and histologic disease activity. Sigmoidoscopy is adequate for assessment of disease activity in patients with UC during follow-up evaluation.