L4-S1 ALIF restores and maintains lordosis while minimizing adjacent segment disease compared to L4-S1 TLIF.

Abstract

The L4-S1 region contributes the most to lumbar lordosis, and adjacent segment disease (ASD) is a common complication following lumbar interbody fusion. To date, no study has directly compared sagittal alignment parameters and incidence of ASD between ALIF and TLIF for the treatment of L4-S1 degenerative disc disease. This study aims to evaluate and compare the efficacy of anterior lumbar interbody fusion (ALIF) versus transforaminal lumbar interbody fusion (TLIF) in restoring L4-S1 lordosis and the impact on the development of ASD. A retrospective cohort study. 102 TLIF patients and 53 ALIF patients were identified from a single-center database. Complications, revisions, and radiological sagittal parameters. We conducted a retrospective study involving patients who underwent L4-S1 fusion for degenerative lumbar disease from January 2017 to December 2021. Patients were categorized into TLIF and ALIF groups, with demographic, surgical, and radiographic data collected. Radiographic parameters were assessed preoperatively, postoperatively, and at final follow-up (45.8 ± 13.2 months). A total of 155 patients were analyzed (102 TLIFs and 53 ALIFs). Both groups exhibited significant changes in L4-S1 lordosis postoperatively; however, ALIF resulted in a more pronounced increase in L4-S1 lordosis (6.5° vs. 1.3°) and reduced compensatory changes at L3/4 compared with TLIF (-2.4° vs. 0.2°). ALIF also maintained 72% of the lordosis restoration over time. Moreover, ALIF had lower incidences of ASD (3.8% vs. 15.7%, p=.034) and significantly fewer reoperations (7.5% vs. 25.5%, p=.009). A binary logistic regression analysis revealed that an increase in postoperative L4-S1 lordosis (OR 0.903 [95% CI: 0.820-0.994]) and a decrease in delta L3/4 (OR 0.757 [95% CI: 0.597-0.961]) were significantly associated with the reduced risk of ASD. ALIF demonstrated superior effectiveness compared to TLIF in restoring and maintaining L4-S1 lordosis, mitigating compensatory lordosis, and decreasing the incidence of ASD. III.