Scoliosis Health Article

Definition

Scoliosis is defined as an abnormal side-to-side or front-to-back curvature of the spine.

Description

When viewed from the rear, the spine usually appears perfectly straight. Scoliosis is a lateral (side-to-side) curve in the spine, usually combined with a rotation of the vertebrae. The lateral curvature of scoliosis should not be confused with the normal set of front-to-back spinal curves visible from the side. While a small degree of lateral curvature does not cause any medical problems, larger curves can cause postural imbalance and lead to muscle fatigue and pain. More severe scoliosis can interfere with breathing and lead to arthritis of the spine (spondylosis).

Approximately 10% of all adolescents have some degree of scoliosis, though fewer than 1% have curves that require medical attention beyond monitoring. Scoliosis is found in both boys and girls, but a girl's spinal curve is much more likely to progress than a boy's. Girls require scoliosis treatment about five times as often. The reason for these differences is not known.

Causes & symptoms

Four out of five cases of scoliosis are idiopathic, meaning that the cause is unknown. Idiopathic scoliosis tends to run in families; genetic screening has identified several different patterns of genetic transmission as of late 2001. In some families, idiopathic scoliosis is transmitted in an autosomal dominant pattern, while in others the mode of inheritance is X-linked. Children with idiopathic scoliosis appear to be otherwise entirely healthy, and have not had any bone or joint disease early in life. Scoliosis is not caused by poor posture, diet, or carrying a heavy book-bag exclusively on one shoulder.

Idiopathic scoliosis is further classified according to age of onset:

• Infantile. Curvature appears before age three. This type is quite rare in the United States, but is more common in Europe.
• Juvenile. Curvature appears between ages three and 10. This type may be equivalent to the adolescent type, except for the age of onset.
• Adolescent. Curvature appears between ages of 10 and 13, near the beginning of puberty. This is the most common type of idiopathic scoliosis.
• Adult. Curvature begins after physical maturation is completed.

Causes are known for three other types of scoliosis:

• Congenital scoliosis is due to congenital birth defects in the spine, often associated with other organ defects.
• Neuromuscular scoliosis is due to loss of control of the nerves or muscles that support the spine. The most common causes of this type of scoliosis are cerebral palsy and muscular dystrophy.
• Degenerative scoliosis may be caused by degeneration of the discs that separate the vertebrae or arthritis in the joints that link them.

Scoliosis causes a noticeable asymmetry in the torso when viewed from the front or back. The first sign of scoliosis is often seen when a child is wearing a bathing suit or underwear. A child may appear to be standing with one shoulder higher than the other, or to have a tilt in the waistline. One shoulder blade may appear more prominent than the other due to rotation. In girls, one breast may appear higher than the other, or larger if rotation pushes that side forward.

Curve progression is greatest near the adolescent growth spurt. Scoliosis that begins early is more likely to progress significantly than scoliosis that begins later in puberty.

More than 30 states have screening programs in schools for adolescent scoliosis, usually conducted by trained school nurses or physical education teachers.