What is scoliosis?

A sideways curve in the spine

Seen from behind, the spine normally looks like a straight line. In scoliosis, the spine curves to the side and the vertebrae rotate around their own axis. Scoliosis is therefore not just a bend but a three-dimensional change in the shape of the spine.

The size of the curve is measured on an X-ray as the Cobb angle. A curve of 10 degrees or more is defined as scoliosis.

Who gets scoliosis?

The most common type is adolescent idiopathic scoliosis, which appears after the age of 10 and has no known cause. Around 2–3% of adolescents have a small degree of scoliosis; only a small proportion of these curves progress far enough to need treatment. Large and progressive curves are considerably more common in girls.

Less commonly, scoliosis results from the spine forming differently before birth (congenital), from muscle and nerve conditions (neuromuscular), from certain syndromes, or from wear of the discs and joints later in life (degenerative).

What causes it?

The exact cause of idiopathic scoliosis is unknown. Genetics play a part: children with a family history of scoliosis are more likely to develop it.

What are the signs?

• One shoulder sitting higher than the other
• One shoulder blade more prominent than the other
• Uneven waist creases, or one hip looking more prominent
• A rib or lower-back hump on one side when bending forward

Adolescent idiopathic scoliosis does not usually cause pain. If there is significant pain or pain that wakes your child at night, numbness, weakness, or any change in bladder or bowel control, be sure to tell your doctor; further tests may be needed.

Will it get worse?

Curves are most likely to progress during growth, especially during growth spurts. That is why regular check-ups are so important for growing children. Once growth is complete, curves under 30 degrees usually do not progress.