Can Unilateral Minimally Invasive Transforaminal Lumbar Interbody Fusion (MIS TLIF) Result in Sufficient Reduction in Spondylolisthesis?: A Comparison with Open TLIF and Bilateral MIS TLIF

ABSTRACT

STUDY DESIGN: Retrospective study. OBJECTIVES: To compare the radiologic results of unilateral or bilateral minimal invasive transforaminal lumbar interbody fusion (MIS TLIF) and conventional open lumbar interbody fusion. SUMMARY OF LITERATURE REVIEW Only a few studies have compared the slip reduction and fusion rate between unilateral or bilateral MIS TLIF and conventional open TLIF. MATERIALS AND METHODS: Between March 2007 and May 2015, 80 patients with single-level low-grade spondylolisthesis underwent unilateral MIS TLIF (26 patients), bilateral MIS TLIF (10 patients), or open TLIF (44 patients) by a single surgeon. Radiologic studies were performed preoperatively, 2 weeks postoperatively, and 12 months postoperatively. Slip reduction, the lumbar lordortic angle, and the fusion rate were analyzed. RESULTS: The 3 groups exhibited significantly improved slip after operation. Significant differences were found among the 3 groups (p=0.015) and between the MIS TLIF group (31.76%±14.42%) and the open TLIF group (41.66%±15.98%) (p=0.01) in the slip reduction rate at 2 weeks after the operation. However, no significant difference was found between unilateral MIS TLIF and bilateral MIS TLIF (37.61%±15.0% vs. 29.5%±13.82%, p=0.148). In the lumbar lordotic angle, no significant difference was found among the 3 groups. There were no significant differences among the 3 groups in slip reduction or the fusion rate at 12 months after the operation. CONCLUSIONS: Our study suggests that unilateral MIS TLIF showed a similar slip reduction and fusion rate to bilateral MIS TLIF, but that conventional open TLIF showed better slip reduction than MIS TLIF, although it had a similar fusion rate.