Spondylolisthesis Reduction and Changes in Sagittal Alignment Following Single-Position Lateral Versus Lateral-Then-Prone Oblique Lumbar Interbody Fusion With Navigation-Assisted Posterior Percutaneous Instrumentation

BACKGROUND AND OBJECTIVES: Lateral interbody fusion represents a minimally-invasive approach to achieve indirect decompression via disc height restoration and alignment correction in patients with degenerative lumbar spondylolisthesis. If the surgeon opts for an anterior-to-psoas ("oblique") corridor, the patient must be positioned in the lateral decubitus position to facilitate interbody placement, which may then be followed by posterior percutaneous pedicle screw placement in either the same lateral decubitus position or by repositioning to prone. It is presently unclear whether operative position significantly affects postoperative spondylolisthesis correction and alignment. We sought to determine the impact of patient positioning on radiographic outcomes and perioperative complications following single-position lateral vs dual-position lateral-then-prone oblique lumbar interbody fusion (OLIF). METHODS: This is a retrospective cohort study at a tertiary academic center. All adult patients undergoing single-level OLIF for degenerative spondylolisthesis were identified and reviewed. Same-level revision cases, patients undergoing additional unrelated procedures, standalone interbody cases, or patients undergoing interbody placement in the prone position were excluded. The primary outcome measures were the percentage reduction in spondylolisthesis and changes in sagittal alignment; secondary outcomes included operative time, radiographic pedicle screw placement accuracy, and complications. RESULTS: We identified 71 cases meeting criteria for the analysis, including 29 (40.9%) single-position and 42 (59.1%) dual-position procedures. Single-position lateral cases lasted on average 29.4 minutes shorter than dual-position cases (95% CI: 11.3-47.6 minutes). There were no statistically significant differences between cohorts in spondylolisthesis reduction, segmental/regional lordosis, or pedicle screw accuracy. CONCLUSION: In this retrospective single-center analysis, single-position lateral OLIF was associated with shorter operative duration compared with dual-position lateral-then-prone OLIF with no significant impact on pedicle screw accuracy or spondylolisthesis reduction. In cases without need for posterior procedures beyond percutaneous instrumentation, surgeons may opt for either approach at their own discretion without clinically significant impact on postoperative alignment or complication rates.