Assistant Professor of Neurosurgery NYU Langone Health New York City, New York, United States
Introduction: Lumbar lateral interbody fusion (LLIF) is a powerful technique for disc height restoration, fusion and deformity correction. Traditionally done in lateral position, prone positioning optimizes operative efficiency and theoretically provides more lordosis. The objective was to describe the feasibility of navigated, prone LLIF (P-LLIF) for adult spinal deformity (ASD) and compare outcomes and radiographic results between single-position P-LLIF and multi-position LLIF.
Methods: A retrospective review of ASD patients who underwent navigation-assisted P-LLIF or standard LLIF was performed. ASD was defined as PI-LL >10 degrees, SVA > 4.5 cm, and/or scoliosis >10 degrees. Perioperative and radiographic outcomes were compared between single-position LLIF vs. multi-position LLIF ASD surgery.
Results: 51 patients underwent navigated P-LLIF, with 45 ASD cases. This study compared 45 P-LLIF (62 interbodies) and 30 LLIF (50 interbodies) patients. Mean age was 66.2, and 38.7% were male. There were no differences in demographics, comorbidities, or surgical variables. Overall LLIF complication rate was 20.0%, and there was no difference between groups (P-LLIF 17.8% vs. LLIF 23.3%, p=0.556). Endplate violation occurred during one P-LLIF due to inaccurate navigation. Mean preoperative SVA, PI-LL mismatch, and scoliosis were 6.4 cm, 20.9 degrees, and 12.2 degrees, respectively; there were no differences between groups. Similar postoperative sagittal plane results were achieved: SVA (4.0 vs 4.6 cm, p=0.519) and PI-LL (11.5 vs. 12.3 degrees, p=0.809). However, P-LLIF afforded greater segmental lordosis correction at L4-L5 (11.4 vs. -4.2 degrees, p=0.040) but not at L1-L2 (5.7 vs. 2.8, p=0.444), L2-L3 (3.0 vs. 0.8, p=0.318), or L3-L4 (2.0 vs. -1.2, p=0.100).
Conclusion : Navigation-assisted P-LLIF for ASD surgery provides a similar complication profile to staged LLIF. It may be a surgical tool to aide in achieving greater lordosis at L4-5, addressing lumbar scoliosis at the apex, and supplement interbody fusions at UIV or around three column osteotomies. Additional studies with long-term follow-up are warranted.
