Open and Minimally Invasive Transforaminal Lumbar Interbody Fusion: Comparison of Intermediate Results and Complications

Study Design: Prospective study. Purpose: To compare clinical and radiological outcomes of open vs. minimally invasive transforaminal lumbar interbody fusion (MI-TLIF). Overview of Literature: MI-TLIF promises smaller incisions and less soft tissue dissection resulting in lower morbidity and faster recovery; however, it is technically challenging. Methods: Twenty-five patients with MI-TLIF were compared with 25 matched open TLIF controls. A minimum 2 year follow-up and a statistical analysis of perioperative and long-term outcomes were performed. Potential complications were recorded. Results: The mean ages for the open and MI-TLIF cases were 44.4 years (range, 19-69 years) and 43.6 years (range, 20-69 years), respectively. The male: female ratio was 13: 12 for both groups. Average follow-up was 26.9 months for the MI-TLIF group and 29.3 months for the open group. Operative duration was significantly longer in the MI-TLIF group than that in the open group (p < 0.05). No differences in estimated blood loss, duration to ambulation, or length of stay were found. Significant improvements in the Oswestry disability index and EQ-5D functional scores were observed at 6-, 12-, and 24-months in both groups, but no significant difference was detected between the groups. Fusion rates were comparable. Cage sizes were significantly smaller in the MI-TLIF group at the L5/S1 level (p < 0.05). One patient had residual spinal stenosis at the MI-TLIF level, and one patient who underwent two-level MI-TLIF developed a deep vein thrombosis resulting in a pulmonary embolism. Conclusions: MI-TLIF and open TLIF had comparable long-term benefits. Due to technical constraints, patients should be advised on the longer operative time and potential undersizing of cages at the L5S1 level.