Pulmonary function studies were reported in sixty-two patients with idiopathic scoliosis with ages ranging between ten and twenty years and were compared with the data obtained from fifty-three normal subjects of a similar age group. Twenty-Six of the normal subjects were siblings of the patients.

Abnormalities in pulmonary function were noted in twenty-nine patients. There was a predominant restrictive type of respiratory abnormality in fourteen, a reduction in pulmonary diffusing capacity in twelve, and a decrease in expiratory flow rates in three. The most common physiological abnormality was a decrease in lung volumes, particularly in vital capacity and its components. Decrease in pulmonary diffusing capacity was usually associated with reduced lung volumes. Pulmonary capillary blood volume was normal in all patients.

One to four years after corrective surgery, follow-up pulmonary function evaluation was repeated in thirty-three patients. In these patients, the average precorrection spinal curve was 62 degrees, and the average final curve after correction and stabilization was 21 degrees. In the postoperative period, improvement of pulmonary function toward normal was observed in twelve patients. Sixteen of thirty-three patients had normal pulmonary function before and after surgical treatment, suggesting that they would have a better chance for their pulmonary status to remain normal in the future because of correction of their spinal curves.