Factors contributing to bracing success in juvenile idiopathic scoliosis and current limitations : a systematic review and meta-analysis.

Abstract

Aims: There is a general lack of guidelines on nonoperative treatment in juvenile idiopathic scoliosis (JIS). This review aims to explore factors determining bracing success in JIS and to identify limitations in current literature.

Methods: A literature search was conducted according to the PRISMA 2020 guidelines. Data extraction focused on the factors affecting bracing success, including pre-brace curve magnitude in Cobb angle, curve type, pre-brace rib vertebral angle difference, in-brace correction, brace type, brace-wear compliance, the time of brace initiation, and bracing duration. Bracing success is defined as 1) avoidance of corrective surgical intervention (curve exceeding 45° at maturity) and/or 2) major curve Cobb angle of < 5° progression at maturity. Meta-analysis was performed for individual factors.

Results: After initial and full-text screening, 16 articles were included in the review. Pooled odds ratio (OR) from eight studies and 560 patients using the threshold of Cobb angle of 30° revealed that patients with pre-brace curve < 30° were associated with bracing success (odds ratio (OR) 3.58; 95% CI 2.26 to 5.65; p < 0.001; I² = 0.08). Major thoracic curves were associated with reduced likelihood of bracing success compared to thoracolumbar/lumbar curves (OR 0.49; 95% CI 0.28 to 0.86; p = 0.010; I² = 0.35). Full-time compliance was significantly associated with bracing success (OR 5.22; 95% CI 2.24 to 12.19; p < 0.001; I² = 0.76).

Conclusion: This review identified that a pre-brace major Cobb angle < 30° and full-time compliance of at least 18 to 20 hours/day are prognostic factors favourable for bracing success, while presence of thoracic curves is prognostic for unfavourable brace outcome. Longer bracing duration does not translate to a higher success rate. Clinicians should devise more efforts to modify patient compliance in order to achieve optimal brace outcomes. The general lack of high-quality evidence and heterogeneity of results in existing studies indicates the need for further rigorous research on JIS.