Short-term effect of surgery for non-idiopathic scoliosis on pulmonary function

Background: Conflicting results are available of effect of surgical correction of scoliosis on pulmonary function. In children with a severely decreased respiratory function even limited improvement of respiratory function after scoliosis surgery could be of major clinical relevance. Aim: This study aimed to evaluate the short-term effect of scoliosis surgery on pulmonary function in children diagnosed with non-idiopathic scoliosis by comparing pre-operative spirometry results to results three months after surgery. Methods: This prospective, single-centre, observational study included children, diagnosed with non-idiopathic scoliosis, able to perform spirometry. Wilcoxon signed-rank test was used to compare spirometry results. Results: 28 children were included with median age of 13 years (interquartile rang (IQR) 10-15). Half were children with neuromuscular disease. There was a statistically significant higher relative expiratory forced vital capacity prior (median 58%, IQR 43-76%) compared to 3 months after surgery (55%, IQR 32-78%), p=0.001). No statistically significant difference of both absolute and relative values of peak expiratory flow and maximal vital capacity were seen prior and after surgery. A trend towards higher relative peak expiratory flow 3 months after surgery was observed (median 60%, IQR 42-77%) versus 50%, IQR 40-88%, p=0.053). Results were similar in the most severely affected children. Conclusion: Spirometry results 3 months after surgery for non-idiopathic scoliosis showed no statistically significant difference compared to results prior to surgery. Even a decline of relative expiratory forced vital capacity was observed.