Vol. 11, Issue 4 (2025)

Background: Degenerative lumbar spondylolisthesis is a common cause of back pain and radiculopathy requiring surgical stabilization when conservative management fails. While open Transforaminal Lumbar Interbody Fusion (TLIF) is the conventional approach, minimally invasive TLIF (MIS-TLIF) has been developed to reduce soft-tissue trauma, perioperative morbidity, and accelerate recovery.
Aim of the study: To prospectively compare perioperative outcomes, functional recovery, and radiological fusion between MIS-TLIF and open TLIF in patients with single-level Low Grade (Grade I& II) degenerative lumbar spondylolisthesis.
Methods: In this prospective comparative study, 28 patients (14 MIS-TLIF, 14 open TLIF) aged 30-65 years with single-level Low Grade (Grade I& II) spondylolisthesis were enrolled. Baseline demographic and clinical data were recorded. Perioperative parameters (operative time, blood loss, hospital stay) were documented. Functional outcomes were assessed using the Visual Analog Scale (VAS) for back and leg pain and the Oswestry Disability Index (ODI) at 1, 3, 6, and 12 months. Radiological fusion was evaluated at 12 months using the Bridwell grading system. Patient satisfaction was assessed using modified Macnab criteria. Statistical analysis included independent t-tests, Mann-Whitney U tests, Chi-square or Fisher’s exact tests, with p<0.05 considered significant.
Results: Baseline demographics were comparable between groups. MIS-TLIF demonstrated significantly reduced operative time (158.5±8.2 vs. 170.3±9.1 min, P=0.01), lower intraoperative blood loss (210.5±10.3 vs. 275.2±15.7 mL, p<0.001), and shorter hospital stay (3.4±0.5 vs. 4.5±0.6 days, p<0.001). Both groups showed significant improvement in VAS and ODI scores; however, MIS-TLIF patients experienced faster and greater functional recovery at all follow-up points (12-month ODI: 17.6±3.2 vs. 23.0±3.5, p<0.001). Complete radiological fusion (Grade I) at 12 months was higher in MIS-TLIF (71.4% vs. 50.0%, P=0.04), with overall fusion success (Grades I + II) also slightly higher (92.9% vs. 85.7%). Modified Macnab criteria showed a trend toward higher “excellent” outcomes in MIS-TLIF (78.6% vs. 64.3%, P=0.32).
Conclusion: MIS-TLIF offers superior perioperative safety and early functional recovery while achieving comparable radiological fusion and patient satisfaction to conventional open TLIF in Low Grade (Grade I& II) degenerative spondylolisthesis. These findings support the use of MIS-TLIF as an effective and less morbid alternative for single-level lumbar fusion.