New surgical developments have dramatically improved treatment of the abnormal sidewise curvature of the spine called scoliosis.

"The development of the Cotrel-Dubbousset device in France in 1984 and its approval by the U.S. Food and Drug Administration in 1986 were milestones in treating scoliosis," said Dr. Gordon Engler, an orthopedic surgeon at New York University Medical Center. "Implanting the device's two rods along the spine results in a more normal spinal contour than could have been achieved with previous surgical techniques."Perhaps its best feature is that no brace or cast is required after surgery. Within a few days the child can be up and moving around freely."

Scoliosis usually begins between the ages of eight and 10. Its two main characteristics are lateral curvature of the spine and rotation of the vertebrae, causing the rib cage to lose its symmetry. Girls are eight times more likely to have scoliosis than are boys. In most cases, the disease appears to be genetic in origin.

"Most of the symptoms of scoliosis are visible to the trained eye, such as an elevated shoulder, an uneven waist or a protruding shoulder blade," Engler noted. "Parents should watch for these early signs."

Approximately 240,000 people in the United States under 16 have a spinal curvature that requires the use of a brace. About 30,000 more need corrective surgery.

"The majority of people who have spinal curvature do not require active medical treatment, because in most cases the disease is not progressive," Engler said.

Surgical procedures to treat scoliosis all involve spine fusion, welding the bones together using the person's own bone as a graft, Engler said.

The Harrington rod implant, first developed in 1959, remains the most commonly used surgical treatment for scoliosis. The Harrington rod corrects the curve in a one-dimensional plane. It cannot derotate the vertebrae as the Cotrel-Dubbousset rods can, the orthopedist said.

A third device that is especially useful in the treatment of scoliosis that affects the lower spine is the Zielke device. Its implantation involves less spine fusion and therefore more mobility.