Curves greater than 40 degrees do not respond to a brace. Curves greater than 60 degrees cause breathing difficulties in adults and require an operation to correct the curve. Curves between 40 and 60 degrees may require surgery as well. However, their children should be screened for scoliosis. Curves greater than 60 degrees are correlated to a shortened life span and can get worse during adult life.
Large curves can lead to arthritis of the spine and premature disablement.
Early treatment can prevent progression and correct a scoliosis. Paediatric Diagnosis and Treatment, 12th Edition. Dr Bill's - Home Page.