Distinct clinical characteristics of adolescent idiopathic scoliosis with asymmetrical ESR1 expression in paraspinal muscle progenitor cells

Background Previous studies found decreased ESR1 expression of concave paraspinal muscle progenitor cells could contribute to the initiation and progression of adolescent idiopathic scoliosis (AIS). The current study investigated the clinical characteristics of AIS with asymmetrical ESR1 expression in paraspinal muscle progenitor cells. Materials and Methods Bilateral deep paraspinal muscle progenitor cells were obtained from 25 consecutive eligible female patients with AIS. RT‐qPCR was performed to evaluate the expression of ESR1. The demographic data (the age at surgery, height, weight, BMI, and age at initiation), posteroanterior and lateral radiographs data (Risser sign, Cobb angle, apical vertebral rotation, and location of apical vertebra), and MR imaging data (bilateral paraspinal muscle CSA ratio and bilateral fatty component ratio) were collected. The correlation between asymmetrical ESR1 expression of paraspinal muscle progenitor cells and the aforementioned clinical characteristics were analyzed. Results Twelve out of twenty‐five patients (48%) showed bilateral ESR1 expression ratio (convex/concave) more than 1.5 folds, and they were divided into the ESR1 asymmetry group. When compared with the ESR1 symmetry group, patients in the ESR1 asymmetry group showed significantly more severe scoliosis (p = 0.041), more hypoplastic concave paraspinal muscle (p = 0.015), and more muscular fatty infiltration in the concave side (p = 0.034). The bilateral ESR1 expression ratio was significantly correlated with Cobb angle (r2 = 0.282, p = 0.006), bilateral paraspinal muscle CSA ratio (r2 = 0.253, p = 0.011), and bilateral fatty component ratio (r2 = 0.248, p = 0.011). Conclusion There were 48% of AIS patients with significantly decreased ESR1 expression in concave paraspinal muscle progenitor cells (convex/concave>1.5 folds), while patients with more asymmetrical ESR1 expression showed more hypoplastic paraspinal muscle and fatty infiltration on the concave side, and more severe scoliotic deformity. Clinical characteristics of AIS with asymmetrical ESR1 expression in paraspinal muscle progenitor cells were investigated. There were 48% AIS patients with significantly decreased ESR1 expression in concave paraspinal muscle progenitor cells, while asymmetrical ESR1 expression was correlated with asymmetrical paraspinal muscle CSA, asymmetrical fatty infiltration, and more severe scoliotic deformity.