Background: Previous studies have shown a significant association between osteopenia and adolescent idiopathic scoliosis (AIS). And initial bone mineral density (BMD) was proposed to serve as a new prognostic factor of curve progression in AIS. However, it remains unknown whether there is a link between the initial bone mineral status and the outcome of brace treatment. This study aimed to investigate whether the initial bone mineral status could influence the final outcome of brace treatment in AIS.
Methods: Girls with AIS treated with brace treatment were recruited. These patients either completed brace treatment, or were indicated for correction surgery with a curve magnitude of >45 degrees. Patients with a progressed scoliosis (group A) and those with a nonprogressed scoliosis (group B) were identified. The associations between the bracing outcome and the indices before bracing, including growth status, anthropometric measurements, BMD status, curve magnitude, and curve pattern were evaluated using univariate analysis and regression analysis.
Results: Sixty-eight patients were included. There were 17 girls (25%) in group A and 51 girls (75%) in group B, respectively. The girls in group A had a significantly larger initial Cobb angle (32.3±6.6 vs. 29.1±5.3 degrees), a significantly lower BMD of lumbar spine from L2 to L4 value (0.80±0.11 vs. 0.88±0.12 g/cm2), and a marginally significantly lower Risser grade (1.4±1.5 vs. 2.2±1.4), than in group B. In comparison with group B, more girls in group A were found to be premenarche (P=0.008), osteopenic (P=0.003), with a lower Risser grade (P=0.079), a greater curve magnitude (P=0.159), and a main thoracic pattern (P=0.122) before the initiation of bracing treatment. As revealed by the multiple logistic regression analysis, osteopenia (P=0.002) was identified as an independent risk factor in curve progression in AIS girls, during the total duration of bracing treatment.
Conclusions: Osteopenia is identified to serve as a new independent risk factor in the curve progression during the duration of bracing treatment. The evaluation of initial BMD status before bracing may help to predict the outcome of brace treatment.
Level of Evidence: Level II.