Curvature of the spine. Coloured magnetic resonance imaging (MRI) scans of frontal sections through the body of a 22-year-old woman with kyphoscoliosis, a progressive deformity of the spine. The spine is at centre, the green blocks are the vertebrae of the spine. Kyphoscoliosis results in an exaggeration of the normal curvature of the spine and a sideways curvature. This condition usually starts in childhood or adolescence, and is most common in girls. Its cause is unknown, although occasionally it may be congenital, or due to polio or an injury. In mild cases no treatment is needed, but in severe cases, as here, surgery is used to straighten and pin the spine.