Digital Assessment of Three-Dimensional Spinopelvic Parameters in Female Lenke Type 1 Adolescent Idiopathic Scoliosis

Study DesignRetrospective cross-sectional study.ObjectivesTo investigate differences and correlations in multi-planar parameters across severity levels in female Lenke type 1 patients, and to identify key factors, thereby providing a basis for personalized preoperative planning.MethodsFull-spine X-rays of 117 female Lenke type 1 patients (40 mild, 40 moderate, 37 severe; aged 10-18 years) were analyzed. Twelve spinopelvic parameters including Cobb angle, apical vertebral translation (AVT), apical vertebral rotation (AVR), thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), sagittal vertical axis (SVA), and spinal tilt (ST) were measured using Mimics 21.0, followed by statistical analysis.ResultsCobb angle, AVT, and AVR increased significantly with severity (<i>P</i> < 0.001). The severe group had greater SVA and smaller ST (<i>P</i> = 0.011; <i>P</i> = 0.038). Regression analysis identified AVT and AVR as significant predictors for moderate (<i>OR</i> = 1.314; <i>OR</i> = 42.094) and severe groups (<i>OR</i> = 1.470; <i>OR</i> = 241.351) (all <i>P</i> < 0.05). In mild and moderate groups, LL showed positive correlations with TK and PI (<i>r</i> = 0.380-0.591) and negative correlations with SVA (<i>r</i> = -0.558; <i>r</i> = -0.332). No significant correlations existed between LL and PI, TK, or SVA in the severe group.ConclusionsIn female Lenke type 1 patients, correcting AVT and AVR is a central surgical objective, as they are integral to coronal and transverse deformities, and AVR also drives sagittal imbalance. LL serves as a pivotal compensation parameter for sagittal balance in these patients. In mild and moderate patients, sagittal balance can be achieved through LL-centric compensation mechanisms. However, in severe patients, LL loses its compensatory role, necessitating surgical intervention to restore sagittal balance.