Lung volumes in scoliosis before and after correction by the Harrington instrumentation method.

Studies of static lung volumes were performed before and after surgery in 92 scoliotic patients, aged 10 to 25 years. The majority of the patients had idiopathic dorsal curves. Vital capacity, total lung capacity, functional residual capacity and residual volume were measured at least 18 months after surgery. A significant increase was observed in all static volumes, averaging 10 per cent; the pre- and postoperative values were expressed in per cent of predicted normal values according to age and height. Correction of body height was taken into consideration in the prediction of normal values. Patients with the more advanced scoliosis had the greatest improvement in lung volumes. The patients were treated postoperatively with a Milwaukee brace for an average of 15 months. The use of this brace, which allows for chest expansions, might account for the improved lung function compared to previous series where plaster body jackets were used. Thus the correction of idiopathic scoliosis by the standard posterior fusion with Harrinton instrumentation together with our postoperative routine provides a lasting reduction of the spinal deformity, prevents progression of respiratory impairment and, in fact, increases the lung volumes, vital capacity, total lung capacity and functional residual capacity by an average of 10 per cent.