- Discussion:
- vital capacity < 75% (of predicted values) is seen in thoracic curves > 75 deg;
- significant reductions in pulmonary function are seen in curves > 80 deg;
- although some effect on pulmonary function can be seen at 60 deg, significant compromise is not seen until the curve is > 90 deg;
- curves greater than 100 deg have total lung capacity of about 50% of normal;
- w/ curves between 100 - 140 deg, average vital capacity is 60%;
- restrictive lung disease and right sided heart failure become manifest at curves about 120 deg;
- Effect of Bracing: (see bracing in scoliosis)
- application of brace results in sig reduction in vital capacity (14%), f(x) residual capacity (22%), & total lung capacity (12%);
- bracing will reduce lung function by 10 to 15%
Changes in residual volume relative to vital capacity and total lung capacity after arthrodesis of the spine in patients who have adolescent idiopathic scoliosis.