Fig. 3

60-year-old female with L4/5 and L5/S1 double-level spondylolytic spondylolisthesis. a The preoperative radiograph demonstrated an obvious lumbosacral deformity (L4–S1 height = 56.9 mm, L4-SVA = 32.5 mm) and sagittal spinal imbalance (L4–S1 lordosis/LL = 48.3%, C7-SVA = 38.2 mm). b Postoperative radiograph after L5/S1 single-level TLIF and posterior instrumentation from L4 to S1 demonstrated an obviously corrected of segmental and global sagittal alignment (L4–S1 height = 64.1 mm, L4-SVA = 22.3 mm, L4–S1 lordosis/LL = 58.6%, C7-SVA = 12.4 mm). c Radiograph at postoperative 3 years revealed a good sagittal spino-pelvic alignment.