For children with congenital scoliosis, malformation of the spine can affect not only posture but also the proper development of internal organs, including the lungs. Normal lung development requires that the rib cage, sternum, and spine be able to move and thus alter the volume of the thoracic capacity as respiration demands. This in turn demands that the thorax be symmetrically shaped and that the diaphragm is secure at the base of the chest.
In patients with scoliosis, however, spinal curvature can cause the vertebrae to protrude into the chest cavity and limit the expansion of the thoracic cavity. When this occurs, the ribs do not have their full range of motion. This can also occur in patients whose scoliosis leads to rib fusion, which restricts movement of the rib cage.
If a child with congenital scoliosis has sufficiently restricted thoracic expansion, known as thoracic insufficiency syndrome (TIS), he or she may experience rapid or labored breathing, feel short of breath, or become fatigued. Children with particularly severe symptoms may need supplemental oxygen or, in the most serious cases, ventilator support. Fortunately, recently-developed treatments have proven highly successful in restoring healthy thoracic growth in these young patients.