[Radiographic characteristics of sciatic scoliosis secondary to lumbar disc herniation]

Objective: To investigate the radiographic characteristics of lumbar disc herniation (LDH) associated with sciatic scoliosis and to compare coronal and sagittal alignment parameters between adolescent and adult patients. Methods: A retrospective analysis was conducted on patients with LDH who underwent unilateral endoscopic discectomy or unilateral laminotomy with discectomy at Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, between January 2017 and July 2025. A total of 86 adolescents with LDH complicated by sciatic scoliosis were included as the adolescent group. Using a random number table, 172 adult patients who met the identical diagnostic and treatment criteria during the same period were selected and matched in a 1∶2 ratio to form the adult group. Based on sagittal balance status, patients were further classified into a balanced group [sagittal vertical axis (SVA)≤40 mm] and an imbalanced group (SVA>40 mm). Spinopelvic sagittal parameters were evaluated. Differences in sagittal and coronal alignment between groups were compared. Furthermore, the associations among the side of disc herniation, the direction of scoliotic curvature, and trunk shift were analyzed. Results: In patients with LDH complicated by sciatic scoliosis, the mean lumbosacral curve was 15.3°±5.8°, the thoracic/thoracolumbar curve was 16.9°±5.4°, apical vertebral translation was (2.9±1.6) cm, and trunk shift was (3.0±1.5) cm. Overall, 79.8% (206/258) of the patients exhibited lumbosacral curve convexity on the same side as the disc herniation, while 81.0% (209/258) demonstrated trunk shift toward the side contralateral to the herniation (both P<0.01). Compared with the imbalanced group, the balanced group showed smaller trunk shift and apical vertebral translation [(2.8±1.2) vs (3.3±1.7) cm and (2.7±1.4) vs (3.1±1.7) cm, respectively, both P<0.05]. Further analysis revealed that adolescents had lower thoracic kyphosis (TK), lumbar lordosis (LL), lower lumbar lordosis, and sacral slope (SS) than adults (13.2°±9.8° vs 17.4°±11.0°, 19.5°±14.2° vs 30.3°±15.6°, 16.7°±11.9° vs 23.8°±11.6°, and 23.4°±6.4° vs 26.7°±8.3°, respectively); while, the SVA and pelvic tilt (PT) were significantly greater than those in adults [(70.5±58.4) vs (41.8±52.6) mm, and 25.7°±10.5° vs 20.8°±9.3°, respectively] (all P<0.05). Conclusions: Patients with LDH complicated by sciatic scoliosis typically exhibit characteristic imaging features, including trunk tilt toward the side contralateral to the herniation, herniation predominantly on the convex side of the lumbosacral curve, and sagittal imbalance. Sagittal imbalance is coupled with coronal deformity and more pronounced in adolescent patients.