Adolescent Idiopathic Scoliosis

Scoliosis is a side-to-side curve in the spine. Adolescent idiopathic scoliosis is a type of scoliosis that develops for reasons that are not understood just before or during the growth spurt of puberty. Adolescent idiopathic scoliosis is the most common type of scoliosis.

In adolescent idiopathic scoliosis, mild curves are more common than moderate or severe curves. Mild curves are the least likely to progress (increase in size over time). Moderate and severe curves are larger in size, and they are more likely to become larger still, particularly if the child is still growing.


Adolescent idiopathic scoliosis can cause the hips and/or shoulders to appear uneven. One shoulder blade or side of the rib cage may stick out more than the other. There may be a difference in how the arms hang beside the body, or the head may appear off-center with the body.

Adolescent idiopathic scoliosis usually develops slowly and without pain. (The exception is fast-growing curves, which may cause pain.) Many times, the change is so gradual that it goes unnoticed by parents and patients. A teacher or coach may notice the effects of the scoliosis first. A pediatrician will be able to confirm the diagnosis.


Often, children are screened for scoliosis at school. In this screening, called the Adams test, a person bends forward until his or her spine is parallel to the ground. A doctor can then examine the back and ribs for symmetry.

A pediatrician or other doctor can confirm the diagnosis by measuring the curve or curves on an X-ray. An X-ray uses invisible beams of radiation to project images of bones and other body structures onto film.

The curves are measured on a scale called the Cobb scale. A mild curve is usually considered a curve that measures 20 degrees or less on the Cobb scale, a moderate curve measures between 20 and 50 degrees, and a severe curve measures 50 degrees or more.

If a patient experiences back pain, other scans, like magnetic resonance (MR) imaging scans, might be performed to rule out any other problems. MR scans use radio waves and a large magnet to produce images of organs and tissues.

Risk Factors

The cause of adolescent idiopathic scoliosis is not understood–in fact, idiopathic means “arising for reasons that are not yet understood.” In some cases, genetics may play a role—about 30% of people with this type of scoliosis have a relative who also has it.

Parents sometimes wonder whether scoliosis is caused by poor posture: it is not.

Scoliosis is more common in girls than boys. Girls’ curves are also more likely to progress and require treatment.


The primary goal of scoliosis screening and treatment is to prevent deformities from progressing to a state where they:

  • Begin to endanger the health of the child by interfering with the heart or lungs
  • Cause symptoms like pain or shortness of breath
  • Reach a magnitude that makes them likely to continue to progress. Curves up to about 40 degrees are unlikely to progress over the course of a lifetime; curves of more than 50 degrees are more likely to progress.

The treatment depends not just on the degree of curvature but also on the patient’s age and skeletal maturity (how much growth is left). A mild curve in a patient who is almost skeletally mature is unlikely to progress further; a moderate curve in a patient with more growth ahead of her is more likely to progress.

Nonoperative treatment, including physical therapy and strengthening and stretching exercises, may be an option for some patients. If the curve is moderate, the doctor may recommend a brace.

If the curve is severe–50 degrees or more–surgery is considered to correct the spinal deformity. The surgeon may perform a correction and fusion procedure, which is the placement of a rod or rods to hold the spine in the correct position until the instrumented segments fuse as a bone.