Spine deformity surgery in the elderly: risk factors and 30-day outcomes are comparable in posterior versus combined approaches

Objectives: Risk factors portending poor outcome following elective spine deformity fusion remain in need of characterization and stratification in the elderly population. Methods: Cases aged >= 60 years who underwent elective posterior or anterior-posterior ('combined') fusion were extracted from the American College of Surgeons National Surgical Quality Improvement Program years 2007-2013 and analyzed by surgical cohort (posterior vs. combined). The 30-day outcomes included operation time, hospital length of stay (HLOS), perioperative complications, and discharge destination. Multivariable regressions controlling for demographic/clinical variables were performed. Odds ratios (OR) and mean differences (B) were reported with 95% confidence intervals (CI). Results: A total of 881 cases (18.2% combined; 81.8% posterior) aged 706.2 years, 32.8% male, and 87.2% Caucasian were included. Posterior fusions associated with extreme body habitus (obese class II/III and underweight; P = 0.027), functional independence (97.5% vs. 91.8%; P = 0.010), and multi-level fusions (7-12 levels: 24.8% vs. 18.1%; >= 13 levels: 8.9% vs. 3.1%; P = 0.004). Overall operation time was 338.0 +/- 150.2-min and HLOS 7.4 +/- 6.6-days; 17.1% suffered early complications and 54.5% were discharged home. On multivariable analysis, combined (B = 63.8-min; P < 0.001), and multi-level fusions (7-12: 61.0-min; P < 0.001; >= 13: 133.8-min; p < 0.001) associated with increased operation time. HLOS increased for multi-level fusions (7-12 levels: 1.3-days; P = 0.012; >= 13 levels: 2.2-days; P = 0.008). Overall complications did not differ by cohort or levels; on post hoc analysis combined fusions associated with pneumonia (OR = 3.05; P = 0.008). Multi-level fusions showed decreased odds of discharge home (7-12 levels: OR = 0.57; P = 0.003; >= 13-levels: OR = 0.41; P = 0.003). Conclusions: The 30-day outcomes and early perioperative complications are comparable for posterior vs. combined approaches to correct deformity in the elderly. Multi-level fusions are associated with increased operation time, HLOS, and discharge to higher level of care.