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

PURPOSE: 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.

METHODS

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).

CONCLUSIONS

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.