Scoliosis is a sideways curvature of the spine that occurs most often during the growth spurt just before puberty. While scoliosis can be caused by conditions such as cerebral palsy and muscular dystrophy, the cause of most scoliosis is unknown. The curve is usually "S"- or "C"-shaped.In some the degree of curve is stable, while in others it increases over time. Mild scoliosis does not typically cause problems, while severe cases can interfere with breathing. Diagnosis is usually confirmed with plain X-rays. Surgical correction is done in curvatures of over 45 degrees and typically involves the use of modern instrumentation systems in which hooks and screws are applied to the spine to anchor long rods, ensuring the correction of the curvature and its stability over time.