The natural history of idiopathic scoliosis. A study of the incidence of treatment

Abstract

The natural history of idiopathic scoliosis has been studied between 1969 and 1985 in a well-controlled population of school children, 66,200 cases, between 7 and 16 years of age. The incidence of scoliosis needing treatment (25 degrees or more in progress in growing children) was studied with a cross-sectional as well as a longitudinal survey. When using a cross-sectional technique, a decrease of cases being treated was seen after the introduction of a conventional screening program--thus indicating a change in the natural history of moderate scoliosis. This could, however, be explained by the consequence of an accumulation of treated cases, formerly diagnosed and treated later on, seen immediately after the introduction of screening. When the longitudinal method was used, this trend could not be observed. And finally, when taking changes of indication of treatment and of the population into consideration, no tendency at all toward a change in the natural history could be seen.