Transforaminal Versus Lateral Lumbar Interbody Fusion: A Comprehensive Systematic Review and Meta-analysis of Radiographic, Perioperative, and Patient-Reported Outcomes

Background: Transforaminal lumbar interbody fusion (TLIF) and lateral approaches such as lateral lumbar interbody fusion (LLIF) are widely used to treat degenerative lumbar disk disease. Although both restore disk height and achieve fusion, comparative advantages in radiographic, perioperative, and patient-reported outcomes (PROs) remain debated. Purpose: To perform an updated meta-analysis comparing TLIF and LLIF with respect to perioperative outcomes, radiographic parameters, complication rates, and PROs. Study Design: Systematic review and meta-analysis. Methods: A comprehensive search of PubMed, Cochrane, and Google Scholar (2000 to 2025) was conducted per Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies directly comparing TLIF and LLIF were included. Random-effects models were used for pooled analyses. Radiographic outcomes were grouped into immediate and 1- to 2-year follow-up. PROs were stratified by early (≤6 months) and late (>6 months) follow-up. Results: Twenty-seven studies (6,047 patients) met inclusion criteria: 4,098 underwent TLIF and 1,949 underwent LLIF. LLIF was associated with shorter surgical time (−14.3 minute; P = 0.04), lower estimated blood loss (−88.3 mL; P < 0.0001), and reduced length of stay (−0.35 days; P = 0.01). LLIF showed greater immediate improvements in mean disk height (+1.68 mm; P = 0.006), foraminal height (+1.80 mm; P < 0.0001), and segmental lordosis (+2.16°; P = 0.03), with lower subsidence risk (odds ratio: 0.40; P = 0.004). TLIF achieved greater immediate canal decompression (+49.8 mm 2 ; P < 0.0001). At late follow-up, LLIF maintained superior disk height (+2.21 mm), foraminal height (+2.33 mm), and segmental lordosis (+3.01°). LLIF was also associated with improved late leg pain scores (Δ −0.23; P = 0.02). Conclusion: LLIF and TLIF each offer distinct advantages. LLIF was associated with lower subsidence risk, reduced blood loss, shorter surgical time, decreased length of stay, and improved radiographic correction. Most PROs were comparable, but TLIF demonstrated improved late leg pain relief. Level of Evidence: III