Vertebra-disc Ratio As a New Predictor for Curve Progression in Early Thoracic AIS with Bracing Treatment

Objectives: Previous studies have reported various predictors for curve progression in braced adolescent idiopathic scoliosis (AIS) patients. However, the reported predictors might be insufficient for patients with early AIS. The aim was to investigate whether the initial vertebra-disc ratio (VDR) could serve as an effective predictor for curve progression in early thoracic AIS (premenarchal and Risser 0) undergoing brace treatment. Patients and methods: This study reviewed a consecutive series of early thoracic AIS girls with thoracic curve. All patients had accepted brace treatment and had regular follow-up. According to the bracing outcomes, patients were divided into two groups: Group P (progressed, curve progressed over six degrees or indicated for surgery) and Group NP (non-progressed). Results: Totally 203 girls were included. There were 73 and 130 patients in Groups P and NP, respectively. The patients in Group P had greater initial VDR (1.9 +/- 0.5 vs. 0.8 +/- 0.4, P < 0.01) than Group NP. During the follow-up, it showed continuous higher values in Group P than Group NP. The logistic regression analysis revealed that initial VDR had an effective value for predicting curve progression in the braced early AIS girls. The ideal cut-off point of initial VDR was 1.5 for the prediction of curve progression. Conclusion: The initial VDR could serve as an effective predictor for curve progression in braced early AIS girls. Evaluation of this new parameter should be carefully performed at the bracing initiation.