Changes in residual volume relative to vital capacity and total lung capacity after arthrodesis of the spine in patients who have adolescent idiopathic scoliosis.

Pulmonary Function in Adolescent Idiopathic Scoliosis Relative to the Surgical Procedure

“…The effect of surgical correction on the pulmonary function of patients with adolescent idiopathic scoliosis is controversial. Although some investigators have shown that surgical correction of scoliosis substantially improves measured pulmonary functions such as vital capacity [4][5][6][7][8][9][10][11] , others have demonstrated no major improvement in pulmonary function after operative correction [11][12][13][14][15] or have reported loss of pulmonary function postoperatively [15][16][17][18][19] . The controversies could perhaps be attributed to the fact that these studies were done on nonhomogeneous populations with different treatment modalities, age distribution, gender, curve patterns, curve severity, and etiology of the scoliosis and with various measurement techniques and parameters of pulmonary function evaluation such as the use of absolute versus percent-predicted values.…”

Correlation of Cobb's angle with pulmonary function in idiopathic scoliosis

“…Some studies suggest a direct correlation, [23,25] and some studies have shown no correlation. [4,6,8] Observations in this study showed that idiopathic scoliosis produces restrictive type of pulmonary defect. Pulmonary parameters such as TV, VC, FVC, FEV 1 , MMEF, PEFR, and MVV were significantly reduced in cases than controls and inversely correlated with the Cobb's angle.…”

“…Many observers have got similar results. [4][5][6]8,28] Hence, the observations of the current study are suggestive of a restrictive defect in scoliosis, which is mainly due to alteration in respiratory mechanics due to the scoliosis.…”

“…However, other factors, such as the distortion of the rib cage associated with the vertebral deformity, may also contribute to the altered ventilation mechanics. [4,6,8,10,11] Some previous studies have shown an obstructive defect in idiopathic scoliosis. [12][13][14][15] Airway obstruction may occur though uncommon.…”

“…[2] Many studies have shown that PFTs of patients with idiopathic scoliosis reveal a restrictive defect. [4][5][6][7][8] Defective mechanical coupling of inspiratory muscles to the chest wall leading to a decrease in respiratory muscle mechanics has been shown to contribute to the restrictive properties. [9] …”