Lateral lumbar interbody fusion to address pseudarthrosis after prior posterior spinal instrumentation

Lumbar pseudarthrosis revision is challenging for both patients and surgeons, with no standard approach. This study aimed to evaluate radiographic fusion and index-level re-revision rates after revision using lateral lumbar interbody fusion (LLIF), comparing standalone LLIF (SA-LLIF) and circumferential LLIF with posterior revision (360°-LLIF). Secondary outcomes included perioperative parameters and sagittal alignment.

This retrospective, single-center cohort study included patients undergoing LLIF for lumbar pseudarthrosis between 2007 and 2023 with ≥ 1-year follow-up. Patients were stratified into SA-LLIF and 360°-LLIF groups. Fusion was assessed at one year using the Bridwell grading system (grades I-II considered fused). Perioperative parameters, re-revision, and sagittal alignment were evaluated.

Thirty-eight patients were included (SA-group: n = 26; 360°-group: n = 12). Groups were comparable except for a higher BMI in the 360°-group (p = 0.035). Overall fusion was 84.2%, with rates of 80.8% in SA-LLIF and 91.7% in 360°-LLIF (p = 0.392). No patient required re-revision for non-union; one 360° patient underwent wound revision. Operative time (233 vs. 84 min, p = 0.005), and estimated blood loss (625 vs. 100 mL, p = 0.001) were higher in the 360°-group. Length of stay and sagittal alignment parameters were similar between groups.

Both 360°-LLIF and SA-LLIF may represent viable revision strategies for pseudarthrosis after posterior instrumentation, each with distinct advantages. Fusion rates were numerically higher with 360°-LLIF but not statistically different, and no patient in either group required secondary revision surgery for non-union. SA-LLIF was associated with shorter operative times and reduced EBL. Findings should be interpreted cautiously given the small sample size.