Assessment of curve progression in idiopathic scoliosis

In a 5-year prospective study on idiopathic scoliosis, an attempt was made to elucidate the natural history of the disease and to determine which factors contribute to curve progression. A total of 85,622 children were examined for scoliosis in a prospective school screening study carried out in northwestern and central Greece. Curve progression was studied in 839 of the 1,436 children with idiopathic scoliosis of at least 10° detected from the school screening program. Each child was followed clinically and roentgenographically for one to four follow-up visits for a mean of 3.2 years. Progression of the scoliotic curve was recorded in 14.7% of the children. Spontaneous improvement of at least 5° was observed in 27.4% of them, with 80 children (9.5%) demonstrating complete spontaneous resolution. Eighteen percent of the patients remained stable, while the remaining patients demonstrated nonsignificant changes of less than 5° in curve magnitude. A strong association was observed between the incidence of progression and the sex of the child, curve pattern, maturity, and to a lesser extent age and curve magnitude. More specifically, the following were associated with a high risk of curve progression: sex (girls); curve pattern (right thoracic and double curves in girls, and right lumbar curves in boys); maturity (girls before the onset of menses); age (time of pubertal growth spurt); and curve magnitude (≥ 30°). On the other hand, left thoracic curves showed a weak tendency for progression. In conclusion, the findings of the present study strongly suggest that only a small percentage of scoliotic curves will undergo progression. The pattern of the curve according to curve direction and sex of the child was found to be a key indicator of which curves will progress. Received: 4 October 1997 Revised: 10 February 1998 Accepted: 11 March 1998