Scoliosis and Chest Cage Deformity Measures Predicting Impairments in Pulmonary Function: A Cross-sectional Study of 492 Patients With Scoliosis to Improve the Early Identification of Patients at Risk

STUDY DESIGN.This study examines the correlations between pulmonary function tests (PFTs) and radiographical measures of spinal deformities in patients with scoliosis. OBJECTIVE.To define the parameters that enable more accurate predictions of restricted pulmonary function (PF) in patients with scoliosis. SUMMARY OF BACKGROUND DATA.The early identification of patients with scoliosis who are at risk of developing severe curve progression and restricted PF is critical to improving patient care. METHODS.A total of 492 patients with a thoracic/thoracolumbar curve (TC) and preoperative PFTs as well as radiographical analysis of the TC and thoracic kyphosis (TK) were assessed. The forced vital capacity (FVC) was expressed as a percentage of the predicted value (FVC%). According to guidelines for the severity of pulmonary impairments, classifications were usedno impairment (FVC > 80%), mild (65 < FVC ≤ 80%), moderate (50 < FVC ≤ 65), and severe impairment (FVC ≤ 50%). Main radiographical parameters were included and statistical analyses were used to identify radiographical predictors and to develop prediction models. RESULTS.The average age was 17 years, 94% of the patients had adolescent idiopathic scoliosis, 20% had lordoscoliosis (TK