Impact of Sagittal Spinal Balance on Functional Recovery After PLIF of L5‐S1 Isthmic Spondylolisthesis With Lumbar Spinal Stenosis

Abstract

ABSTRACT Objective Despite the widespread use of posterior lumbar interbody fusion (PLIF) for L5‐S1 isthmic spondylolisthesis (IS) with lumbar spinal stenosis (LSS), residual sagittal imbalance critically impairs long‐term pain relief and functional recovery. This study analyzes the influence of residual sagittal imbalanceon health‐related quality of life (HRQOL) after PLIF for L5‐S1 IS with LSS, aiming to optimize surgical correction and prognostic accuracy. Methods This study analyzed 103 consecutive patients with L5‐S1 IS and LSS undergoing PLIF from 2020 to 2022, followed at 3 days, 3 months, and ≥ 1 year postoperatively, using SPSS 26.0 for statistical analysis. Preoperatively, patients were stratified into balanced (SVA ≤ 50 mm) and unbalanced (SVA > 50 mm) groups. Postoperatively, the unbalanced group was reclassified into postoperative balanced (SVA ≤ 50 mm) and postoperative unbalanced (SVA > 50 mm) groups. Spinal parameters—including SVA, slip degree (SD), disc height (HOD), lumbar lordosis (LL), pelvic tilt (PT), and pelvic incidence (PI)—and clinical outcomes (Oswestry Disability Index [ODI], Visual Analogue Scale [VAS]) were analyzed preoperatively and postoperatively to assess surgical efficacy. Postoperative unbalanced group. Results In the balanced and unbalanced groups, SD and HOD significantly improved postoperatively versus preoperative values (p 0.05), while the unbalanced group exhibited marked improvements in these parameters (p 0.05), whereas it improved in the postoperative balanced group (p < 0.05). The postoperative balanced group also achieved better SVA, SD, HOD, LL, and PT outcomes versus the postoperative unbalanced group (p < 0.05). ODI and VAS scores improved across all groups postoperatively, with the balanced group and postoperative balanced group outperforming their counterparts at final follow‐up (p < 0.05). Conclusion Preoperative and postoperative sagittal balance are pivotal determinants of long‐term functional recovery and HRQOL in patients undergoing PLIF for L5‐S1 IS with LSS.

Keywords

• isthmic spondylolisthesis
• lumbar spinal stenosis
• posterior lumbar interbody fusion
• sagittal balance