MIS-TLIF Versus Open TLIF in Combined Lumbar Stenosis and Low-Grade Spondylolisthesis : Of Discharge Timing and Treatment Pricing

An open-label, randomized, noninferiority clinical trial. To determine the effectiveness of the MIS-TLIF over the O-TLIF in patients with symptomatic lumbar stenosis combined with low-grade spondylolisthesis by comparing the clinical efficacy and safety. In patients with combined lumbar spinal stenosis and spondylolisthesis, it remains uncertain whether minimally invasive fusion surgery is noninferior to the open approach. We conducted an open-label, noninferiority trial involving patients with symptomatic lumbar stenosis combined with low-grade spondylolisthesis. Patients were randomly assigned in a 1:1 ratio to undergo either MIS-TLIF or open TLIF surgery. The primary endpoint was the reduction in the Oswestry disability index (ODI) score from baseline to three months postsurgery, with a noninferiority margin of 12 points. Secondary outcomes included three-month changes from baseline in back and leg pain, neuropathic pain, satisfaction with treatment, intraoperative data, and cost-effectiveness. In the modified intention-to-treat population, the mean difference was 0.4, with the corresponding 90% CI of -5.7 to 6.5, having a lower bound below the noninferiority margin of 12. Similar results were obtained by analysis of the per-protocol population. 82.8% of patients achieved the MCID for the ODI. Results for secondary outcomes (clinical scales, complications) showed no significant differences between the treatment groups (all P >0.05). Although the open TLIF group had a hospital stay that was 1.5 days longer ( P =0.005) and required additional analgesia more frequently ( P =0.026), direct costs were 10.5% higher in the MIS-TLIF group ( P <0.001). This is the first high-quality study comparing open TLIF and MIS-TLIF with a validated primary endpoint. Among patients with combined lumbar degenerative stenosis and degenerative spondylolisthesis, MIS-TLIF resulted in clinical outcomes at three months that were noninferior to those with open TLIF.