The Efficacy of Posterior Lumbar Interbody Fusion in Restoring Sagittal Balance

Introduction: Interbody fusion procedures, including posterior (PLIF), transforaminal (TLIF), anterior (ALIF), and lateral (LLIF), have been effectively used to treat lumbar degenerative pathologies and provide spinopelvic balance. Lumbar spine interventions mainly aim to improve or restore sagittal alignment and correct lordotic curve. Recently, spinopelvic parameters have been investigated in many series of studies through many factors including disc height, pelvic tilt, sacral slope and lumbar lordotic curve. The pelvic incidence also was described as a morphological parameter that was not affected by either posture or pelvis position.

Methods: Fifty-Eight patients (36 females and 22 males; mean age: 51 ± 15 (range: 33–68 years old) with degenerative disc prolapse or spondylolisthesis cases were included in the study. Patients were operated upon by posterior lumbar interbody fusion (PLIF). The disc height, level and grade of listhesis if present, and spinopelvic parameters including pelvic tilt, sacral slope, pelvic incidence (PI) and lumbar lordotic curve, were measured on digital X-rays. All preoperative and postoperative clinical and radiological parameters were assessed.

Results: There was a statistically significant improvement in both visual analog scale (VAS) scores and Oswestry Disability Index (ODI) were 2 and 20, respectively (p < 0.05). On the same bank, there was significant increase in disc height immediate
postoperative, with p-value < 0.05. In addition, there was a statistically significant improvement in mean of lumbar lordotic curve in immediate postoperative follow up with p- value < 0.05, but no significant change after 6 months follow-up with p-value >0.05.

Conclusion : Patients presenting with degenerative lumbar spine pathologies benefit posterior lumbar interbody fusion and show statistically significant improvement of sagittal balance and other spino-pelvic parameters. They also show improvement in segmental, regional, and global coronal plane alignment.