Supine ALIF versus Lateral-Decubitus OLIF for Degenerative Lumbar Disease

STUDY DESIGN: Systematic review and meta-analysis. OBJECTIVE: To compare outcomes between supine anterior lumbar interbody fusion (ALIF) and lateral decubitus oblique lumbar interbody fusion (OLIF). BACKGROUND: ALIF and OLIF differ in surgical corridor and patient positioning, with their relative advantages remaining debated. METHODS: A PRISMA-compliant search of PubMed, Embase, and Google Scholar was performed through April 2026 for studies evaluating anterior versus oblique lumbar interbody fusion. Outcomes included perioperative, complication, patient-reported, and sagittal alignment measures, pooled using fixed- or random-effects models based on heterogeneity (I²>50%). RESULTS: Thirteen studies (1,432 patients; 795 ALIF, 637 OLIF) met inclusion criteria. OLIF was associated with shorter length of stay (-0.87 days [95% CI: -1.47 to -0.26], P=0.005). Leave-one-out analyses demonstrated lower operative time (-39.07 minutes [95% CI: -76.73 to -1.41], P=0.04) and estimated blood loss (-96.32 mL [95% CI: -182.03 to -10.61], P=0.03) favoring OLIF, though substantial heterogeneity persisted. Complications and patient-reported outcomes did not differ. OLIF showed greater reductions in sagittal vertical axis (SVA) immediately postoperatively (-18.32 mm [95% CI: -30.89 to -5.75], P=0.004) and at final follow-up (-9.39 mm [95% CI: -17.83 to -0.96], P=0.03). In a subanalysis of fusions involving the sacrum, OLIF had lower EBL (-182.32 mL [95% CI: -297.38 to -67.27], P=0.002) and shorter LOS (-1.45 days [95% CI: -1.72 to -1.18], P<0.00001), with a similar operative time trend (-72.83 min [95% CI: -147.48 to 1.81], P=0.06). CONCLUSIONS: OLIF appears to offer a modest advantage over ALIF, with shorter hospitalization, comparable complications and patient-reported outcomes, and greater SVA correction. These perioperative benefits could potentially be meaningful in patients with higher comorbidity burden and appeared preserved in fusions involving the sacrum. The SVA correction may reflect advantages of single-position lateral surgery for restoring global alignment. LEVEL OF EVIDENCE: III.