Scoliosis is a condition in which there are abnormal side-to-side curves in the spine.

What is Scoliosis?

Scoliosis is a condition in which your spine curves sideways in a C or S shape. Some curvature in the spine is normal — even necessary. Spinal curves help us maintain healthy alignment and balance in our back, shoulders, and pelvis. However, when abnormal or exaggerated spinal curves develop, we call it scoliosis.

Normal spine illustration


Scoliosis is somewhat rare, affecting just 2% of women and 0.5% of men in the general population. Many conditions can cause or be associated with scoliosis, including cerebral palsy, spina bifida, muscular dystrophy, spinal muscular atrophy, and tumors. However, over 80% of cases are idiopathic — meaning there is no known cause — and are often diagnosed in otherwise healthy people.

There are four main types of scoliosis:

  1. Idiopathic: no known cause, most common
  2. Congenital: spine forms incorrectly before birth
  3. Neuromuscular: caused by a neuromuscular disorder
  4. Early onset: diagnosed before age 10


Idiopathic scoliosis means there is no known cause to explain why the spine develops a curve. It is the most common type of scoliosis, representing 80% of cases. There are four categories of idiopathic scoliosis, based on age of diagnosis:

  1. Infantile: diagnosed at 3 years old or younger
  2. Juvenile: diagnosed between 3 and 9 years old
  3. Adolescent: diagnosed between 10 and 18 years
  4. Adult: diagnosed after skeletal maturity
Male Scoliosis spine

Although idiopathic scoliosis can occur at any age, it is usually diagnosed during adolescence when growth spurts make the condition apparent. Adult cases can be the result of an undiagnosed or untreated case of adolescent idiopathic scoliosis, although they are more often the result of known curves continuing to progress into adulthood. Some studies have found a significant risk of progression if a curve is greater than 50 degrees at maturity.

Depending on the severity of the curve, idiopathic scoliosis may be treated with observation, bracing, or corrective surgery.


Congenital scoliosis (present at birth) is caused by malformation of the spine during prenatal development. The spinal column develops during the third to sixth week in utero at the same time as several other major organ systems, including the bladder, kidneys, and heart. As a result, congenital vertebral anomalies tend to be associated with other malformations. 

In congenital scoliosis, one or more of the following malformations occurs:

  • The vertebrae do not form correctly
  • One or more vertebrae are absent
  • Vertebral imbalance (hemivertebra) causes spine to grow crooked 
  • Bones do not fully separate during growth (unilateral bar)

When two or more malformations occur together, scoliosis can progress very rapidly.

If the spinal malformations are minor, observation  may be an appropriate treatment. For more severe cases, surgery can be performed to achieve spinal balance while preserving as much height as possible. However, surgeries of his kind should be attempted only by those surgeons with experience in treating congenital spinal malformations. Bracing is rarely used as a primary treatment for congenital scoliosis, as it hasn’t been proven to significantly alter any abnormal growth patterns caused by spinal malformations.

The goal for treating congenital scoliosis is to allow the spine to grow as much as possible and to help the child reach the end of growth with a reasonably straight, balanced spine. Experts are increasingly recognizing that allowing the chest cavity and lungs to develop fully should be an essential consideration in the treatment plan.


Neuromuscular scoliosis (NMS) occurs in children with a neuromuscular disorder that impairs their ability to control the muscles that support their spine. Common conditions associated with NMS include cerebral palsy, spina bifida, muscular dystrophies, and spinal cord injuries. 

NMS is a progressive condition that worsens during periods of rapid growth. As the child grows and their muscles weaken, the spinal curve will become more pronounced. If a child uses a wheelchair, the progressive spinal curves may make it hard for them to sit comfortably, affecting their quality of life. 

Because neuromuscular scoliosis is associated with a variety of other medical issues, treatment must be individualized to each child. Bracing may help support the child’s torso but will not usually prevent progression. Seating inserts into a wheelchair may also help with support and positioning but is also not a corrective solution. Implanting a baclofen pump to inject Botox into the paraspinal musculature can reduce other neuromuscular symptoms but will not treat NMS.

Ultimately, the child’s family and doctors will have to work together to determine whether preforming corrective surgery to preserve the child’s ability to sit will improve the child’s quality of life. It’s a difficult decision given the risks, costs, and recovery associated with the surgery. For children with cognitive or sensory impairment, the decision can be especially challenging as parents are unable to explain the surgery or the resulting pain to their child. Many parents find it helpful to talk to other families who have gone through the experience.


Early onset scoliosis (EOS) is diagnosed in patients younger than 10 years old. Some EOS cases are idiopathic, which is called idiopathic early onset scoliosis. Idiopathic EOS is further broken into two categories:

  • Infantile Idiopathic Scoliosis: diagnosed before age 4
  • Juvenile Idiopathic Scoliosis: diagnosed between ages of 4 to 10 

EOS can also be caused by congenital abnormalities, neuromuscular disorders, or certain syndromes.

When left untreated, EOS is sometimes associated with heart and lung problems, which in severe cases may increase risk for early death. The combined spine and lung problems in EOS are referred to as thoracic insufficiency syndrome (TIS).

Idiopathic EOS with curves greater than 30 to 35 degrees are likely to progress and will require treatment. Infantile idiopathic curves less than 35 degrees will likely resolve without treatment as the child grows.