Understanding idiopathic scoliosis

The term scoliosis is used to describe a condition, which represents an abnormal curvature of the spine, but it is not a disease or a diagnosis. Scoliosis can be caused by congenital, developmental or degenerative problems, but most cases of scoliosis actually have no known cause, and this is known as idiopathic scoliosis.

Scoliosis usually develops in the thoracic spine (upper back) or the thoracolumbar area of the spine, which is between the thoracic spine and lumbar spine (lower back). It may also occur just in the lower back. The curvature of the spine from scoliosis may develop as a single curve (shaped like the letter C) or as two curves (shaped like the letter S).

While there are many forms of scoliosis, four of the most common ones include:

Congenital scoliosis. This is a relatively rare form of congenital malformation of the spine. These patients will often develop scoliotic deformities in their infancy.
Neuromuscular scoliosis. This may occur when the spine curves to the side due to weakness of the spinal muscles or neurologic problems. This form of scoliosis is especially common for individuals who cannot walk due to their underlying neurolomuscular condition (such as muscular dystrophy or cerebral palsy). This may also be called myopathic scoliosis.
Degenerative scoliosis. Scoliosis can also develop later in life, as joints in the spine degenerate and create a bend in the back. This condition is sometimes called adult scoliosis.
Idiopathic scoliosis. By far the most common form of scoliosis is idiopathic scoliosis, which most often develops in adolescents and typically progresses during the adolescent growth spurt. Because it most often occurs during adolescence, this condition is sometimes called adolescent scoliosis.

Idiopathic scoliosis

This is by far the most prevalent form of scoliosis and occurs to some degree in approximately one half million adolescents in the US. There is no known cause of idiopathic scoliosis (“idiopathic” refers to a disease or condition or unknown origin) although it does tend to occur in families.

Idiopathic scoliosis is usually categorized into three age groups:

From birth to 3 years old - called infantile scoliosis.
From 3 to 9 years old - called juvenile scoliosis.
From 10 to 18 years old – called adolescent scoliosis.

This last category, from 10 to 18 years old, comprises approximately 80 percent of all cases of idiopathic scoliosis (See Figure 1).

The risk of curvature progression is increased during puberty, when the growth rate of the body is the fastest. Scoliosis with significant curvature of the spine is much more prevalent in girls than in boys, and girls are eight times more likely to need treatment for scoliosis, because they tend to have curves that are much more likely to progress. Still, the majority of all cases of scoliosis do not require treatment.

It is important to note that idiopathic scoliosis results in spinal deformity, and is not typically a cause of back pain. Of course, people with scoliosis can develop back pain, just as most of the adult population can develop back pain. However, it has never been found that people with idiopathic scoliosis are any more likely to develop back pain than the rest of the population.