Technical Feasibility and Early Outcomes of Minimally Invasive Transforaminal Lumbar Interbody Fusion with Large-Footprint Cage via Tubular Approach: A Novel Surgical Technique

Abstract Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) has become a widely accepted technique for the management of degenerative lumbar spine pathologies. Traditionally, standard TLIF cages have a relatively small footprint, providing limited endplate coverage. Larger-footprint cages are typically inserted through anterior or lateral approaches. The study aimed to describe the surgical technique of MIS-TLIF using a large-footprint cage (MIS-LTLIF) and evaluate its early feasibility and safety. A prospective analysis was conducted on 30 patients (39 levels) who underwent MIS-LTLIF for degenerative lumbar spine disease. After standard tubular docking over the facet joint, complete facetectomy was performed to create a wide window between the exiting and traversing nerve roots. After meticulous disc space preparation, the cage was inserted and rotated in a reverse orthogonal maneuver to orient it in the horizontal position. All these patients were assessed with parameters including blood loss, operative time, pre- and postoperative days 14 visual analog scale (VAS) and Oswestry disability index (ODI) scores, and any other postoperative complications. Statistical analysis was performed using a paired t-test. Preliminary findings demonstrate that insertion of large-footprint cage is feasible via MIS-TLIF approach Our average cage size was 40 × 15 × 10 mm, and the average operative time was 1 hour 55 minutes per level. VAS (back pain) improved preoperatively from 8.00 ± 0.87 to 4.22 ± 0.97 (p = 0.000039), while VAS (leg pain) improved from 8.22 ± 0.83 to 1.67 ± 0.51 (p = 0.000000017) postoperatively. The ODI score improved from 59.78 ± 4.87 to 21.22 ± 2.68 (p < 0.001) indicating statistically significant improvement. Only one patient complained of postoperative unilateral radicular pain, which got relieved with medication over 2 weeks and one patient had cage migration, which was realigned following the same steps of the surgery. MIS-LTLIF represents a novel, minimally invasive modification of the conventional MIS-TLIF technique that facilitates the placement of a large-footprint cage. By combining the advantages of posterior minimally invasive access with the biomechanical benefits of wider-footprint cages, this technique has the potential to bridge the gap between MIS-TLIF and anterior/lateral fusion strategies.