Bone, Joint and Muscle Conditions


What Is Scoliosis?

Scoliosis measurements drawn by Kit M. Song, MD

Scoliosis spine curves measured using the Cobb method.

Scoliosis is a sideways curve in the spine. On an X-ray, most children's spines look straight. The spines of children with scoliosis curve to the side, like the shape of the letters S or C.

Many children have slight side-to-side curves in their spines. They usually do not need treatment. In children with scoliosis, the bones of the spine (vertebrae) have greater than 10 degrees of tilt.

Kinds of Scoliosis

There are different kinds of scoliosis:

Functional scoliosis

Functional scoliosis is a curvature due to a problem that does not involve the spine, such as having legs that are different lengths or muscle spasms caused by pain. These can cause a child to lean to the side, creating the appearance of scoliosis.

The curvature, however, is flexible and will go away if the problem that causes the child to lean to the side goes away.

Structural scoliosis

In structural scoliosis, the spine curvature is not flexible and does not go away with a change in position.

There is no evidence that functional scoliosis will lead to structural scoliosis.

Idiopathic structural scoliosis

Idiopathic means we do not know the definite cause of the problem. This is the case for 80% of children with structural scoliosis. We do know that children with idiopathic structural scoliosis do not have other health conditions associated with scoliosis.

Structural scoliosis associated with other conditions

In about two out of every 10 cases, children with structural scoliosis also have one of these conditions:

  • Born with vertebrae that do not develop normally (congenital scoli)
  • An underlying problem in the brain or spinal cord, such as a cyst or a tumor.
  • A problem with nerves or muscles, such as cerebral palsy or muscular dystrophy (MD).

Scoliosis in Children

Between one and three of every 100 children have a measurable curve in their spines (more than 10 degrees of tilt on an X-ray) that does not have a known cause (idiopathic scoliosis). But only about two of every 1000 children ever gets a curve that is large enough to need treatment.

Equal numbers of boys and girls have the smaller curves that need no treatment. Girls are seven times as likely as boys to have the larger curves in their backbones.

Scoliosis at Seattle Children's

Our team is known nationally for treating all kinds of spinal deformities in children. We have treated thousands of children with scoliosis, ranging from teenagers with idiopathic scoliosis to children with forms of the condition that involve their nerves and muscles. Each year, the team from our Spine Program evaluates 500 to 600 children with spine problems.

At Seattle Children's, we offer your child the support of an entire medical center. Complex spine cases usually involve bigger, more severe curves that are more difficult to correct and affect the spinal cord and lungs. In caring for children with these more difficult cases, we often work with experts in children's lungs (pediatric pulmonary specialists) and nervous systems (neurosurgeons).

Our surgical spinal cord monitoring team leads the country in developing new techniques for making back surgery safer. We have developed recent advances in spinal cord monitoring and treatment of scoliosis in very young children (infantile scoliosis).

Reducing the number of surgeries for severe scoliosis

Our surgeons helped introduce a technology that reduces surgeries for kids with severe scoliosis -- and improves their lives. Read more.

Contact Us 

Contact Orthopedics and Sports Medicine at 206-987-2109 for an appointment, a second opinion or more information.