Study design: A retrospective study.
Objective: To determine the definite cut-off value of initial correction rate (ICR) that could be predictive of bracing outcome in patients with adolescent idiopathic scoliosis.
Summary of background data: Earlier studies showed that braced patients with a better ICR could finally have a higher probability of successful outcome. However, it remains controversial what definitive cut-off value of ICR is required to accurately predict the outcome.
Materials and methods: A cohort of 488 adolescent idiopathic scoliosis patients who have completed the brace treatment with a minimum of 2-year follow-up were included in the current study. Curve progression of ≤5 degrees was used to define the success of brace treatment. The success group and the failure group were compared in terms of initial Risser sign, initial age, sex, curve pattern, initial curve magnitude, and ICR. The receiver operating characteristics curve was used to define the definite cut-off point of initial curve correction rate. A logistic regression model was created to determine the independent predictors of the bracing outcome.
Results: At the beginning of brace treatment, the mean age of the cohort was 13.2±1.5 years, and the mean curve magnitude was 29.5 ± 6.6 degrees. At the final follow-up, 368 patients were successfully treated by bracing. Compared with the success group, the failure group was found to have significantly younger age, lower Risser sign, and lower ICR. According to the receiver operating characteristic curve, the best cut-off value of ICR was 10%. The logistic regression model showed that ICR was significantly associated with the outcome of brace treatment with an odds ratio of 9.61.
Conclusions: Patients with low ICR, low Risser sign, and young age could have a remarkably high risk of bracing failure. A rate of 10% was the optimal cut-off point for ICR, which can be used to effectively stratify braced patients.