Following posterior spinal fusion for adolescent idiopathic scoliosis, patients with asthma are at increased odds of pulmonary adverse events.

Background: Posterior spinal fusion (PSF) is a highly successful treatment for adolescent idiopathic scoliosis (AIS). Asthma is one of the most common illnesses affecting young patients and has been shown to affect outcomes in orthopedic procedures. The correlation of asthma and postoperative adverse outcomes following PSF had not been well characterized. Methods: Adolescent patients undergoing PSF for AIS between 2015 and 2023 were identified using the national administrative PearlDiver M165 database. Those with versus without asthma were matched 1:4 based on demographic and comorbid factors and compared for incidence of 90-day postoperative adverse events using multivariable logistic regression. Revision surgery within 5 years was compared using Kaplan-Meier analysis and the log-rank test.Secondary multivariable analysis was performed comparing odds of 90-day postoperative adverse events for different levels of asthma severity (mild intermittent, mild persistent, moderate/severe) relative to non-asthma patients. Results: Of 10,196 PSF patients meeting study criteria, asthma was noted for 1,616 (15.8%). After matching, those with asthma were at higher odds of respiratory failure (odds ratio [OR] 1.98, p < .001), pneumonia (OR 1.72, p = .004), and atelectasis (OR 1.52, p = .002), as well as emergency department visit (OR 1.66, p < .001) and readmissions (OR 1.58, p < .001). Differences were not identified for non-pulmonary adverse events. As asthma severity increased from mild intermittent, to mild persistent, to moderate/severe, odds ratios incrementally increased pneumonia (OR not significant, not significant, 4.52, respectively), respiratory failure and atelectasis (OR not significant, not significant, 2.38, respectively) (p < .05 for each listed). Conclusion: Overall, asthma is a common comorbidity for adolescent patients undergoing PSF for AIS and is associated with higher odds of postoperative pneumonia, respiratory failure, and atelectasis. These adverse outcomes increase with increased asthma severity. These findings may help in patient counselling and expectations for postoperative management.