Minimally invasive transforaminal interbody fusion for high-grade spondylolisthesis: a retrospective study analysis of a tailor-made solution

Study Design: Retrospective study. Purpose: We investigated cantilever reduction and fusion technique in high-grade spondylolisthesis (HGS) with minimally invasive surgery-transforaminal interbody fusion (MIS-TLIF). Overview of Literature: Most publications that describe minimally invasive surgeries for HGS, especially grade 4 or 5 listhesis, utilized a combined anterior and posterior approach. To the best of our knowledge, a detailed report that provides specific technical nuances for optimal use of a posterior-only approach utilizing MIS-TLIF is greatly lacking. Methods: This study included 36 patients with HGS in whom reduction, posterior instrumentation, and fusion were achieved with MIS- TLIF. They were evaluated for lower back pain and radicular pain, scaled by Visual Analog Scale (VAS) score. Erect radiographs were performed to calculate slip angle (SA) and sacropelvic and spinopelvic parameters preoperatively, postoperatively, and at each follow-up until 4 years. Results: This study identified 30 patients with grade III HGS and six patients with grade IV/V HGS. Spinopelvic parameters were unbalanced in 13 patients. Complete reduction was achieved in 24 patients, with end-stage reduction of grade I with adequate spinopelvic balance achieved in 12 patients. Intraoperative neuromonitoring demonstrated no loss of signals throughout the procedure in any of the patients. Excellent functional outcome was achieved with back pain as well as leg pain VAS score improvements postoperatively in all patients. No implant-related complications or pseudoarthrosis incidences were reported at long-term follow-up at 4 years. Conclusions: MIS-TLIF for HGS is a specific solution for a complex pathology, enabling one to achieve an excellent clinical as well as radiological outcome.