Changes of sagittal spino-pelvic alignment in scoliosis patients in standing and supine position

Objective To compare the influence of different position and diverse pathogeny in patients on sagittal spino-pelvic balance. Methods One hundred and ten patients with scoliosis were included in this retrospective study. They were divided into four groups according to pathogeny:idiopathic scoliosis group (n=31), congenital scoliosis group (n=36), neuromuscular scoliosis group (n=32) and degenerative scoliosis group (n=11). Sagittal vertical axis (SVA), thoracic kyphosis (TK), thoracolumbar kyphosis (TLK), lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS) were measured on preoperative upright and supine lateral radiographs. Results The TK and PT decreased, and SS increased when the position changed from standing to supine in the four groups (P< 0.05). Compared with the other three groups, the SVA, LL, PI and PT of degenerative scoliosis group showed statistically significant difference no matter in which positions. The LL of degenerative scoliosis group increased (P< 0.05) when the position changed from standing to supine. In contrast, the LL of idiopathic and neuromuscular scoliosis group decreased (P< 0.05). However, the congenital scoliosis group showed no significant difference in LL. Conclusion This study shows that the sagittal alignment of scoliosis in standing position is different with which in supine position. And neither in upright nor in supine position, the sagittal parameters of degenerative scoliosis is different with the idiopathic, congenital and neuromuscular scoliosis.