Impaired lung function and relationship to spinal deformities in patients with adolescent idiopathic scoliosis: a systematic review and meta-analysis

Abstract

Introduction: Patients with adolescent idiopathic scoliosis (AIS) display certain degree of compromised lung function, but the evidence on its exact relation remains unclear. Our team summarised the associations between various lung function parameters and radiographic features in patients with AIS. Methods: A systemic search in electronic database for original studies reporting association between lung function and spinal deformity in patients with AIS was performed. Multiple independent reviewers extracted data and evaluated quality of the included studies. Pearson correlation and 95% confidence intervals for associations between various pulmonary and spinal parameters were calculated using random-effects meta-analysis. Results: Fifteen studies (1907 participants) were included. Several spinal deformity parameters were significantly related to lung functions (eg, % forced vital capacity [FVC], % forced expiratory volume in 1 second [FEV1], % total lung capacity [TLC]) in AIS patients. Patients with impaired lung function demonstrated significantly larger thoracic Cobb’s angles and less thoracic kyphosis than healthy controls. Meta-analyses from 10 studies showed that main thoracic Cobb’s angles were negatively related to %FVC, %FEV1, %TLC, and %VC. Conversely, thoracic kyphosis angles were positively associated with %FVC, %FEV1, and %TLC. Conclusion: This is the first systematic review and meta-analysis to summarise the associations between pulmonary function and spinal deformity in patients with AIS. Although it has been reported that patients with severe thoracic Cobb’s angle display significant pulmonary impairments, our findings suggest that pulmonary impairment exists even in patients with mild-to-moderate idiopathic scoliosis. Future research should investigate the effectiveness of non-surgical/surgical means in restoring the lung function of these patients after accounting for confounders.