Scoliosis

Abnormal curvature of the spine.

Beginning in childhood or adolescence, scoliosis curves the spine so that the shape of the body is distorted. The disease can cause pain, deformity, and other medical problems if not properly treated. Scoliosis is defined medically as a sideways (lateral) spinal curvature of eleven degrees or more. Only lateral curvatures constitute scoliosis, as distinct from an excessive rounding of the back with rounded shoulders and sunken chest (hyperkyphosis) or an abnormal forward curve of the lower back (hyperlordosis, also called swayback). Scoliosis eventually pulls the rib cage out of its normal position, crowding the ribs inside the curve and pulling those outside it apart. If severe enough, it can damage internal organs and impair breathing. In cases where scoliosis is painful, the pain is generally increased by bending, extended standing, and heavy work.

The lateral curvatures of scoliosis are either C- or S- shaped. The C-shaped right thoracic curve shifts the ribs on the right side and can squeeze the heart and lungs. Lower C-shaped curves include the thoracolumbar curve, stretching from the thoracic vertebrae to the lumbar region, and the lumbar curve, which twists the hips. The most common S-shaped curve is the double major curve, which consists of a curve in the chest area and one going in the opposite direction in the lumbar area. S-shaped curves generally cause less deformity because the two parts balance each other out somewhat. The spinal curvatures of scoliosis are measured by a method known as Cobb's angle, which is the angle created by the intersection of lines perpendicular to the top and bottom vertebrae of the curve. Having a standard of measurement allows for accurate and consistent communication between physicians. It also allows the progress of a single patient to be accurately tracked over time.

Roughly 80% of scoliosis cases are idiopathic, meaning that they have no known cause. The remainder are caused by a variety of conditions, including birth defects, chronically poor posture, uneven leg lengths, accidental injuries, nerve and muscle diseases such as muscular dystrophy and poliomyelitis, and diseases of the connective tissues, such as Marfan's syndrome and osteogenesis imperfecta. Idiopathic scoliosis is known to have a hereditary component.

While idiopathic scoliosis usually appears in adolescence, the disorder may also begin in childhood or infancy. When it occurs in infants, it affects males more frequently than females, at a ratio of 3:2. Unlike scoliosis that is diagnosed at later ages, infantile idiopathic scoliosis (onset between birth and 3 years of age) usually corrects itself. Although scoliosis at this age is virtually unknown in the United States and Canada, it is as common as the adolescent form in other parts of the world. In contrast to infantile scoliosis, the juvenile variety (onset between ages four to 10) is equally common among boys and girls and, like the adolescent variety, shows a hereditary influence. Scoliosis is most likely to become apparent during the growth spurts between ages 10 and 15, when it strikes 2-3% of young people. In this age group, girls are affected three times as often as boys and are 10 times more likely than boys to have spinal curvatures of 30 degrees or more.

Early warning signs of scoliosis are generally provided by children's posture and the fit of their clothes. One hip or shoulder might be higher than the other, and the head may tilt, or a shoulder blade protrude. One arm may look longer than the other, or there may be asymmetric creases at the waist. When the child bends over, the ribs tend to form a hump on one side. Uneven hemlines or pant legs are other common clues. When signs of scoliosis appear, prompt diagnosis is important. Early treatment with a brace can prevent the need for surgery later on. Many states require schools to have screening programs for scoliosis, and the American Academy of Pediatrics recommends that physicians check youngsters for the condition during routine office visits every other year between the ages of 10 and 16. The Scoliosis Research Society and the American Academy of Orthopedic Surgeons recommend screening girls at the ages of 10 and 12 and boys at either 13 or 14. When scoliosis is suspected, a physician performs a detailed examination, including χ rays, to determine the shape and severity of the spinal curvature.

Treatment of scoliosis ranges from simple monitoring to surgery. Decisions about treatment are based on the age, gender, and general health of the child, as well as the severity and nature of the curvature. Mild curvatures under 25 degrees often require no treatment other than periodic examinations and χ rays to monitor the condition. Special exercises may also be recommended to help strengthen the back. Only 20% of mild spinal curvatures worsen, and only 3 in 1,000 become serious enough to require treatment. Treatment of moderate curves, 25 to 40 degrees, varies depending on the age of the patient. The younger the patient is at the onset of symptoms, the more severe the curves are likely to become.

The treatment for moderate scoliosis in children who are still growing is a lightweight brace, custom molded to fit the body, that can be worn for 16-24 hours a day. These braces, which come up only as high as the underarms and usually don't show underneath clothing, have proven 85% effective in arresting spinal curvatures. They can be removed for showering and swimming, and they allow for a much higher activity level than the traditional braces. If the curvature is high up in the spine, a full torso brace may be most effective, although young people are more reluctant to wear these.

An alternative treatment for moderate scoliosis is electronic stimulation ("electronic bracing"), in which electrodes are placed on the skin during sleep, stimulating the muscles to contract and straighten the spine. Like conventional braces, electrosurface stimulation only works for curvatures under 40 degrees, and in patients whose bones are still growing. While some researchers have found this method 80% effective in halting the progress of scoliosis curves, others have questioned its effectiveness.

For treatment of severe scoliosis (curves of 40-50 degrees) surgery may be necessary, especially if the curve continues to worsen even with a brace or there is pain that does not respond to treatment. Only about one of 100 cases of scoliosis is serious enough to warrant surgery. It is estimated that as many as a third of all spinal operations are for severe scoliosis. The most common operation is the Harrington rod technique, in which metal hooks attached to the vertebrae at the top and bottom of the curve hold metal rods that straighten the spine and hold it in place. Small bone fragments taken from the hip or ribs are inserted between the vertebrae, promoting the growth of solid bone which then fuses the vertebrae together within six to eight months. A brace or body cast is worn for a period of weeks or months after the operation. Newer surgical techniques that are gaining popularity include the use of two rods to provide additional balance and more correction of the curve; use of wires instead of hooks to hold the rods in place; and the Luque method, in which numerous wires pass through the neural canal and are attached to slim rods on either side of the curve. These newer methods require shorter periods of hospitalization, and patients may not need to wear body casts during the recovery period. Scoliosis is not outgrown in adulthood. Adults with the condition should have their spinal curvatures monitored by a physician at least once a year.

Scoliosis

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