Scoliosis

Scoliosis is a sideways curve of the spine, often described simply as curvature of the spine. Seen from behind, a spine with scoliosis looks more like an S or a C than a straight line, and the curve is usually accompanied by some rotation. It is common, and most curves are mild, cause no symptoms, and never need treatment. What matters is the size of the curve, whether it is getting worse, whether it is causing pain or pressing on nerves (most often in adults), and, with a large curve in the chest, whether it is starting to affect the lungs and breathing.

If scoliosis treatment is needed, it will depend on what type of scoliosis it is. A curve in a growing child raises different questions compared to a curve that develops later in life through spinal wear and degeneration. The sections below help explain the difference.

Scoliosis is grouped by its cause, and the two that matter most in practice are the first two below:

• Idiopathic (no known cause): by far the most common, making up around 80% of cases. It has no single identifiable cause and usually appears during childhood growth, most often as adolescent idiopathic scoliosis, which is more common in girls and is generally painless. This is worth stating plainly, because people often ask what they did to cause it: idiopathic scoliosis is not caused by posture, by carrying a heavy bag, or by sleeping position, despite how often those are blamed.
• Degenerative (adult): develops later in life as the discs and facet joints wear unevenly and let the spine curve. This is the type most likely to cause back and leg pain.
• Congenital: present from birth, when the vertebrae do not form properly in the womb.
• Neuromuscular: caused by a condition affecting the nerves or muscles that support the spine, such as cerebral palsy, muscular dystrophy, or spina bifida.

Scoliosis is measured on a standing X-ray as the Cobb angle, the angle of the curve. A curve of 10 degrees or more counts as scoliosis, and the size of the angle determines what treatment what, if any, is required.

Mild (10 to 25 degrees): often causes no symptoms and, especially once growth has finished, may simply be monitored.

Moderate (25 to 45 degrees): more noticeable, and in a child who is still growing this is the range where a brace is usually considered to stop it worsening.

Severe (more than 45 to 50 degrees): more likely to progress and to cause symptoms or visible imbalance, and the range where surgery is usually discussed. A very large curve in the chest can also begin to restrict the lungs and breathing.

As with other spine conditions, the angle guides treatment decisions but does not tell the whole story, particularly in adults, where the clinical symptoms such as any pain or nerve issues are more important.

The right operation depends above all on age, and on whether the problem is the curve itself or the symptoms it causes. The below 3 images are for illustration only.