Unilateral biportal endoscopic lumbar interbody fusion (ULIF) versus minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) for the treatment of degenerative lumbar spondylolisthesis: a retrospective analysis

Abstract Objective: This study retrospectively compared the early clinical and imaging outcomes of the single-level Meyerding Grade Ⅰ degenerative lumbar spondylolisthesis (DLS) between unilateral biportal endoscopic lumbar interbody fusion (ULIF) and minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) using an expandable tubular retractor system under a surgical loupe. Methods: This was a retrospective study. This study included fifty-five patients (twenty-eight patients underwent ULIF and twenty-seven patients who underwent MI-TLIF at the Affiliated Hospital of Jiangsu University from June 2020 to July 2021. Demographic characteristic, surgical parameters, laboratory results, and clinical and imaging outcomes were collected and compared between the two groups. Results: The mean estimated blood loss was significantly lower in the ULIF group (P<0.001). However, the mean operative time was significantly longer than in the ULIF group than in the MI-TLIF group (P<0.05). The mean CK and CRP levels on the first postoperative day were significantly lower in the ULIF group (P<0.001). All clinical scores improved significantly after the operation in both groups. The VAS back score for pain at two weeks and 1 month postoperatively was significantly lower in the ULIF group (P<0.05). There was no significant difference between the two groups in the change in the dural sac cross-sectional area preoperatively or at the final postoperative follow-up. The fusion rate was significantly greater in ULIF at 6 months after the operation (P<0.05). Conclusion: Compared to MI-TLIF, the ULIF technique has the advantages of less hemorrhage, less inflammation, and earlier fusion. However, this approach has a limited operation time. However, further clinical outcomes need to be followed up in the longer term.