STUDY DESIGN: Meta-Analysis. OBJECTIVE: This meta-analysis will compare transforaminal lumbar interbody fusion (TLIF) to Anterior lumbar interbody fusion (ALIF) at L5-S1 in lumbar degenerative spine diseases (DSD). BACKGROUND: Interbody device placement is indicated for alignment correction, sustaining decompression, achieving fusion, and is an effective and widely performed surgical treatment for lumbar DSD. ALIF and TLIF are the two most commonly performed approaches for the management of DSD at L5-S1. METHODS: Following the PRISMA guidelines, PubMed, Cochrane, and Google Scholar (pages 1-20) were accessed and explored until December 2024. The extracted data consisted of complications, reoperations, surgery-related parameters, patient-reported outcome measures (PROMs), and post-operative radiographic parameters. Across all studies, mean differences (MD) with 95% CI were used for continuous data while odds ratio (OR) was utilized for dichotomous data. RESULTS: Nine retrospective articles were included in the meta-analysis, including 1292 patients, with 694 in the TLIF group and 598 in the ALIF group. Patients undergoing TLIF were found to have higher rates of overall complications (OR=1.66
P=0.005) and reoperations (OR=5.92
P=0.03
although 2 studies were included in this analysis), shorter operative time in MIS TLIF compared to ALIF (MD=-47.00
P<
0.001), more blood loss in open TLIF compared to ALIF (MD=135.05
P<
0.001), and less improvement in lumbar lordosis and segmental lordosis (MD=-3.48
P=0.03
MD=-5.86
P<
0.001). However, there was no difference in PROMs between the 2 groups. CONCLUSION: Patients undergoing TLIF at L5-S1 for their DSD, compared to ALIF, had higher rates of complications and reoperations, greater blood loss, and less improvement in sagittal alignment. These results highlight the efficacy, power, and safety of ALIF and its benefits in restoring alignment, which may optimize long-term outcomes.