Loss of body height due to severe thoracic curvature does impact pulmonary testing results in adolescents with idiopathic scoliosis.

A standing body height is a variable used to calculate pulmonary parameters during spirometry examination. In adolescents with idiopathic scoliosis, the loss of the body height is observed, and it may potentially influence the results of pulmonary testing. The study aimed to analyze pulmonary parameters in adolescents with idiopathic scoliosis in relation to the measured versus the corrected body height. Preoperative pulmonary testing and radiographic evaluation were performed in 39 children (29 females, 10 males) aged 12-17 years. Forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) were measured. The single best effort was analyzed. Thoracic Cobb angle ranged 50°-104°. Corrected body height was calculated according to the Stokes' formula. The subgroup analysis was performed for the subjects with curves 50°-74° (N=26) versus 75°-104° curves (N=13). Mean measured body height was 166.1±9.0 cm versus 168.9±8.9 cm mean corrected body height. The %FVC obtained for the measured height was significantly higher than obtained for the corrected height: 84.6% ±15.6 vs. 81.6% ±15.6, p<0.001. The %FEV1 obtained for the measured height was significantly higher than obtained for the corrected height: 79.8% ±16.3 vs. 77.35% ±15.9, p<0.001. The subgroup analysis revealed significant differences in %FVC and %FEV1 calculated for the measured versus the corrected body height, p<0.001. Corrected body height significantly influences the results of pulmonary parameters measurement. In consequence, it may influence the analysis of the pulmonary status of children with idiopathic scoliosis.