1247 Bridging the Gap: ALIF Outshines TLIF in Radiographic Reduction of L5-S1 Spondylolisthesis

Abstract

INTRODUCTION: Both the ALIF and TLIF are established surgical approaches for treating Grade 1 or 2 L5-S1 spondylolisthesis. Additionally, each procedure poses different complication profiles. There is a rising debate regarding ALIF versus TLIF regarding multiple outcomes including reduction of spondylolisthesis, thus, we aimed to compare our rates of radiographic reduction. METHODS: We conducted a retrospective review of isolated L5-S1 TLIF or ALIF surgeries at our tertiary care center from 2012-2022. These cases were reviewed for demographics, follow-up, preoperative parameters, surgical characteristics, postoperative parameters, radiographic outcomes, reduction rates and complications encountered. The inclusion criteria were minimum age of 18 years and a grade 1 or 2 spondylolisthesis at L5-S1 treated with ALIF or TLIF. We excluded patients with previous instrumentation, trauma, infection, and no spondylolisthesis. RESULTS: Of the 156 patients screened, 98 patients were specifically treated for this condition. The ALIF group (n = 40) had a higher rate of complete reduction of spondylolisthesis (90%) compared to the TLIF group (n = 58) (62.1%, p = 0.008). The TLIF group had a higher rate of partial reduction (84%, n = 21) compared to the ALIF group (16%, n = 4). Gender distribution differed significantly between the groups, with the ALIF group comprising 30% males and 70% females, while the TLIF group included 62.1% males and 37.9% females (p = 0.004). Baseline radiographic measures revealed a significant difference in Sagittal Vertical Axis (SVA), with the ALIF group exhibiting a lower average SVA (1.1 ± 3.3) compared to the TLIF group (4.3 ± 2.5, p = 0.005). CONCLUSIONS: Although further research is required, when discussing options with patients regarding surgical approaches for Grade 1-2 spondylolisthesis, ALIF demonstrates higher radiographic reduction rates than TLIF at L5-S1.