Comparative analysis of single-stage versus two-stage fusion surgeries for adult spinal deformity: radiographic outcomes, clinical improvements, and complication rates.

Abstract

To compare single-stage and two-stage corrective fusion surgeries for adult spinal deformity (ASD), focusing on radiographic and clinical outcomes, and surgery-related complications. A retrospective cohort study of 245 ASD patients who underwent spinal fusion surgery involving three or more vertebral levels was conducted. Patients were categorized into single-stage and two-stage groups. Propensity score matching was performed to adjust for age, surgical procedure, and radiographical parameters. Radiographic parameters, complication rates, and the Japanese Orthopaedics Association (JOA) score were compared RESULTS: After matching for clinical background, the two-stage group showed longer surgery times (493.7 ± 157.2 min vs. 271.3 ± 125.7 min, p < 0.001) and greater estimated blood loss (1617.1 ± 1276.9 mL vs. 1067.5 ± 1274.0 mL, p < 0.001). Surgery-related complication rates were similar between the two groups (20.0% vs. 20.0%, p = 1.000). At two years post-surgery, the two-stage group demonstrated significantly superior JOA score improvement (100.9 ± 84.5% vs. 68.2 ± 62.6%, p = 0.017), lower pelvic tilt (23.6 ± 11.3° vs. 29.1 ± 14.7°, p = 0.023) and a trend towards smaller sagittal vertical axis (40.6 ± 42.7 mm vs. 58.9 ± 58.7 mm, p = 0.075). Comparative analysis with matched clinical backgrounds revealed that the two-stage approach maintained equivalent complication rates while achieving sufficient correction effects and favorable clinical score improvements at two years post-surgery. To elucidate the relationship between individual surgical strategies and personalized complication risks, further research is necessary.