Impact of Increasing Age on Outcomes of Spinal Fusion in Adult Idiopathic Scoliosis

Objective To investigate the role of advancing age on postoperative complications and revision surgery after fusion for scoliosis. Methods A retrospective, cohort study was performed using the Thomson Reuters MarketScan database, examining patients with adult scoliosis who underwent spinal fusion from 2000 to 2009. Primary outcomes included infection, hemorrhage and pulmonary embolism (PE) within 90 days of surgery, and refusion. The effect of increasing age was estimated using the odds ratio (OR) of complications in a multivariate logistic regression analysis, and a Cox proportional hazard model estimated the hazard ratio of refusion. Results A total of 8432 patients were included in this study. Overall, the average age was 53.3 years, with 26.90% males and 39% with a Charlson Comorbidity Score of ≥1. Most patients had commercial insurance (66.81%), with 26.03% and 7.16% covered by Medicare and Medicaid, respectively. Increasing age (per 5-year increment) was a significant predictor of hemorrhagic complication (OR, 1.06; confidence interval [CI], 1.01-1.11; P = 0.0196), PE (OR, 1.09; CI, 1.03-1.16; P = 0.0031), infection (OR, 1.04; CI, 1.01-1.07; P = 0.0053), and refusion (hazard ratio, 1.07; CI, 1.02-1.13; P = 0.0103). Conclusions In this study, age was associated with increased risk of hemorrhage, PE, infection, and refusion. With the aging population, the role of patient age on postoperative healing and outcomes deserves deeper investigation after repair of adult idiopathic scoliosis.