Comparative evaluation of perioperative outcomes and radiographic findings in older patients undergoing TLIF versus OLIF surgeries for multi-level lumbar spinal stenosis

The objective of this study was to compare the observed perioperative, clinical, radiographic and 2-year follow-up outcomes associated with Oblique Lateral Lumbar Interbody Fusion (OLIF) and Transforaminal Lumbar Interbody Fusion (TLIF) in older patients diagnosed with multi-level lumbar spinal stenosis. Retrospective analysis was conducted on data sourced from prospective studies, encompassing patients with multi-level lumbar spinal stenosis treated between June 2022 and June 2023. All patients who with multi-level lumbar spinal stenosis underwent TLIF or OLIF were retrospectively analyzed and divided into OLIF and TLIF groups. Comprehensive perioperative data, patient-reported outcomes (PROs), and radiographic assessments were gathered and compared both immediately postoperatively and at the 2-year follow-up. A total of 79 patients were enrolled. The TLIF group had greater estimated blood loss and a longer postoperative hospital stay ( P < 0.001). Postoperatively, the OLIF group had lower drainage volume, earlier time to first ambulation, shorter drain duration, and shorter urinary catheter duration ( P < 0.05). At 2-year follow-up, the OLIF group achieved the minimum clinically important difference (MCID) for Oswestry Disability Index (ODI), Visual Analogue Scale (VAS), Mental and Physical Component Summaries of the SF-36 scales more frequently than the TLIF group. In multivariable analyses, OLIF remained associated with a shorter postoperative hospital stay, earlier ambulation, and higher odds of achieving the 2-year MCID for the ODI, VAS-back, VAS-leg, SF-36 PCS, and SF-36 MCS. Both groups showed significant improvement in sagittal parameters (toracic kyphosis (TK), lumbar lordosis (LL)) and local intervertebral disc parameters (intervertebral foramen height (IFH), anterior disc height (ADH) and posterior disc height (PDH)) after surgery, with greater improvements observed in the OLIF group. These parameters were well maintained in both groups during the 2-year follow-up. In this retrospective cohort, for older patients diagnosed with multi-level lumbar spinal stenosis, OLIF was associated with more favorable perioperative recovery, higher rates of clinically meaningful improvement, and greater restoration of selected radiographic parameters than TLIF. These findings should be interpreted as observational associations rather than evidence of a causal or superior treatment effect.