Comparison of posterolateral fusion and posterior lumbar interbody fusion for treatment of degenerative spondylolisthesis: Analysis of spino-pelvic sagittal balance and postoperative chronic low back pain

•Both PLF and PLIF can improve clinical outcomes for degenerative spondylolisthesis.•PLIF can achieve better restoration of spino-pelvic sagittal balance parameters compared with PLF.•PLIF can lead to lower incidence of postoperative chronic low back pain than PLF. This study aims to compare the spino-pelvic sagittal balance and clinical outcomes of patients treated with posterolateral fusion (PLF) and posterior lumbar interbody fusion (PLIF) for degenerative spondylolisthesis. A total of 72 patients (28 patients treated with PLF and 44 patients treated with PLIF) were studied. The spino-pelvic sagittal balance, Numerical Rating Scale (NRS), and Oswestry Disability Index (ODI) of the PLF and PLIF groups were compared. The incidence of postoperative chronic low back pain (improvement of NRS less than 50%) in the two groups was also recorded. Significant restoration of spino-pelvic sagittal balance was observed in the PLIF group after surgery. Both groups achieved significant improvements in NRS and ODI postoperatively. Significant differences in postoperative lumbar lordosis and pelvic tilt were found between the PLF and PLIF groups. Significant difference in the incidence of postoperative chronic low back pain was also detected between the two groups. PLF and PLIF can improve the clinical outcomes of patients with degenerative spondylolisthesis. PLIF can achieve better restoration of spino-pelvic sagittal balance parameters and less incidence of postoperative chronic low back pain than PLF.