A new risk classification rule for curve progression in adolescent idiopathic scoliosis

Background context: Prognostic factors for curve progression of adolescent idiopathic scoliosis (AIS) have been reported previously. There is only one existing rule that classifies AIS patients into two groups by a curvature of 25°.

Purpose: This study aimed to develop a more refined risk classification rule for AIS.

Study design: This was a retrospective cohort study.

Patient sample: We examined 2,308 untreated AIS patients, aged 10 years and older, who had a Risser sign of 2 and lesser and a curvature less than 30° at presentation.

Outcome measures: Outcome was taken as the time to progression to 30°.

Methods: Patients' clinical parameters were analyzed by Classification and Regression Tree analysis.

Results: The new classification rule identified four risk groups of curve progression. Patients with a curvature of 26° and more and less than 18° constituted the highest and lowest risk groups, respectively. The two intermediate groups were identified by the age (11.3 years), menarcheal status, and body height (154 cm).

Conclusions: The risk classification rule only uses information at the first presentation and can aid physicians in deriving an efficient management.