Single-Position Prone Lateral Lumbar Interbody Fusion Increases Operative Efficiency and Maintains Safety in Revision Lumbar Spinal Fusion

Study Design. Multi-centre retrospective cohort study.Objective. To evaluate the feasibility and safety of the single-position prone lateral lumbar interbody fusion (LLIF) technique for revision lumbar fusion surgery.Background Context. Prone LLIF (P-LLIF) is a novel technique allowing for placement of a lateral interbody in the prone position and allowing posterior decompression and revision of posterior instrumentation without patient repositioning. This study examines perioperative outcomes and complications of single position P-LLIF against traditional Lateral LLIF (L-LLIF) technique with patient repositioning.Method. A multi-centre retrospective cohort study involving patients undergoing 1 to 4 level LLIF surgery was performed at 4 institutions in the US and Australia. Patients were included if their surgery was performed via either: P-LLIF with revision posterior fusion; or L-LLIF with repositioning to prone. Demographics, perioperative outcomes, complications, and radiological outcomes were compared using independent samples t-tests and chi-squared analyses as appropriate with significance set at P<0.05.Results. 101 patients undergoing revision LLIF surgery were included, of which 43 had P-LLIF and 58 had L-LLIF. Age, BMI and CCI were similar between groups. The number of posterior levels fused (2.21 P-LLIF vs. 2.66 L-LLIF, P=0.469) and number of LLIF levels (1.35 vs. 1.39, P=0.668) was similar between groups. Operative time was significantly less in the P-LLIF group (151 vs. 206 min, P=0.004). EBL was similar between groups (150mL P-LLIF vs. 182mL L-LLIF, P=0.31) and there was a trend toward reduced length of stay in the P-LLIF group (2.7 vs. 3.3d, P=0.09). No significant difference was demonstrated in complications between groups. Radiographic analysis demonstrated no significant differences in preoperative or postoperative sagittal alignment measurements.Conclusion. P-LLIF significantly improves operative efficiency when compared to L-LLIF for revision lumbar fusion. No increase in complications was demonstrated by P-LLIF or trade-offs in sagittal alignment restoration.