Scoliosis uses the 45 to 50° threshold as a result of the well-documented, plus or minus 5° measurement error that can occur while measuring Cobb angles. Surgeons who are specialized in spine surgery perform surgery for scoliosis. To completely straighten a scoliotic spine is usually impossible, but for the most part, significant corrections are achieved. The two main types of surgery are: One or both of these surgical procedures may be needed. The surgery may be done in one or two stages and, on average, takes four to eight hours. A 50-year follow-up study published in the "Journal of the American
Management of scoliosis plaster jacket applied early may be used instead of a brace. It has been proven possible to permanently correct cases of infantile idiopathic scoliosis by applying a series of plaster casts (EDF: elongation, derotation, flexion) on a specialized frame under corrective traction, which helps to "mould" the infant's soft bones and work with their growth spurts. This method was pioneered by UK scoliosis specialist Min Mehta. EDF casting is now the only clinically known nonsurgical method of complete correction in progressive infantile scoliosis. Complete correction may be obtained for curves less than 50° if the treatment begins before the second