RT Journal Article SR Electronic T1 Short- and Mid-Term Outcomes Following ALIF and TLIF in L5-S1 Isthmic Spondylolisthesis Patients JF International Journal of Spine Surgery JO Int J Spine Surg FD International Society for the Advancement of Spine Surgery SP 8696 DO 10.14444/8696 A1 Chi, Jialun A1 Woods, Kate S. A1 Vengsarkar, Ved A. A1 Xu, Zhiwen A1 Yang, Hanzhi A1 Kumar, Abhishek A1 Zhang, Yi A1 Zhang, Zhichang A1 Wang, Jesse A1 Labaran, Lawal A1 Jin, Li A1 Li, Xudong YR 2025 UL https://www.ijssurgery.com/content/early/2025/01/13/8696.abstract AB Background A limited number of studies have compared the outcomes of anterior lumbar interbody fusion (ALIF) to transforaminal lumbar interbody fusion (TLIF) for the treatment of isthmic spondylolisthesis. This study aims to compare postoperative complications between these two surgical approaches.Methods A retrospective review was performed using a large national database. The study population included all patients older than 18 years who underwent single-level ALIF or TLIF with a diagnosis of L5 to S1 isthmic spondylolisthesis. A 1:2 propensity score was used to match ALIF and TLIF cohorts for age, sex, and relevant comorbidities, including smoking status. Multivariate logistic regression was used to compare 3-month and 2-year medical and surgical complications, including 5-year reoperation rates.Results Five hundred and seventy-eight ALIF patients were paired with 1,156 TLIF patients following the match. The analysis revealed a higher 3-month ileus rate in ALIF patients (P = 0.009) and a lower, though not significant difference in, reoperation rate for ALIF within 2 years at 7.1% compared with TLIF at 7.7% (P = 0.696). Five-year reoperation rates were comparable (9.5% vs 10.8%; P = 0.612).Conclusions Aside from the increased rate of ileus in the ALIF group, there was no significant difference in both short- and mid-term complications, including overall reoperation rate, between the 2 techniques. Spine surgeons should select the optimal technique for a given patient.Clinical Relevance ALIF and TLIF offer comparable mid-term postoperative outcomes for treating 1-level L5/S1 isthmic spondylolisthesis.Level of Evidence 3.