Adolescent idiopathic scoliosis is an abnormal curvature of the spine that appears in late childhood or adolescence. Instead of growing straight, the spine develops a side-to-side curvature, usually in an elongated "s" or "C" shape, and the bones of the spine become slightly twisted or rotated. In many cases, the abnormal spinal curve is stable; however, in some children, the curve becomes more severe over time (progressive). For unknown reasons, severe and progressive curves occur more frequently in girls than in boys. The cause of adolescent idiopathic scoliosis is unknown. It is likely that there are both genetic and environmental factors involved. Treatment may include observation, bracing and/or surgery.

The term "idiopathic" means that the cause of this condition is unknown. Adolescent idiopathic scoliosis probably results from a combination of genetic and environmental factors. Studies suggest that the abnormal spinal curvature may be related to hormonal problems, abnormal bone or muscle growth, nervous system abnormalities, or other factors that have not yet been identified.

Researchers suspect that many genes are involved in adolescent idiopathic scoliosis. Some of these genes likely contribute to causing the disorder, while others play a role in determining the severity of spinal curvature and whether the curve is stable or progressive. Although many genes have been studied, few clear and consistent genetic associations with this condition have been identified.

Adolescent idiopathic scoliosis is characterized by an abnormal curvature of the spine (usually in an elongated "S" or "C" shape), along with twisted or rotated bones of the spine. Mild scoliosis generally does not cause pain, problems with movement, or difficulty breathing. It may only be diagnosed if it is noticed during a regular physical examination or a scoliosis screening at school. The most common signs of the condition include a tilt or unevenness (asymmetry) in the shoulders, hips, or waist, or having one leg that appears longer than the other. A small percentage of affected children develop more severe, pronounced spinal curvature.

Scoliosis can occur as a feature of other conditions, including a variety of genetic syndromes. However, adolescent idiopathic scoliosis typically occurs by itself, without signs and symptoms affecting other parts of the body.

Treatment of adolescent idiopathic scoliosis may involve observation, bracing and/or surgery. Treatment recommendations are generally dependent upon the risk of curve progression. Curves progress most during the rapid growth period of the patient (adolescent or pre-adolescent growth spurt). The potential for growth is evaluated by taking into consideration the patient's age, the status of whether females have had their first menstrual period, and radiographic parameters (x-ray studies).

Detailed information about these treatment options can be accessed through the Scoliosis Research Society.

Adolescent idiopathic scoliosis can be sporadic, which means it occurs in people without a family history of the condition, or it can cluster in families. The inheritance pattern of adolescent idiopathic scoliosis is unclear because many genetic and environmental factors appear to be involved. We do know, however, that having a close relative (such as a parent or sibling) with the condition increases a child's risk of developing it.