Lateral lumbar interbody fusion (LLIF) is a minimally invasive technique increasingly used to address degenerative lumbar pathologies, including spondylolisthesis, degenerative disc disease, and adult degenerative scoliosis. This type of fusion surgery involves the placement of interbody cages, facilitating indirect neural decompression and spinal realignment while reducing disruption of posterior musculature and soft tissue. However, the optimal supplemental fixation strategy-stand-alone cages, unilateral pedicle screws, or bilateral pedicle screws is debated. Bilateral pedicle screw fixation has been the norm, yet emerging biomechanical evidence suggests that unilateral fixation may provide comparable stability, with the added benefits of reduced operative time, lower costs, and preservation of contralateral anatomy. Stand-alone LLIF, performed without additional fixation, has shown promising results in select patients, although there are still issues with subsidence and long-term fusion integrity.
While previous studies have compared stand-alone LLIF to bilateral fixation, no research has directly assessed clinical outcomes across all three approaches (stand-alone, unilateral, and bilateral fixation). This prospective cohort study directly compares clinical results among these three approaches. Patients undergoing LLIF were stratified into stand-alone, unilateral fixation, or bilateral fixation groups based on surgical technique. Demographics (age, sex, smoking status) and patient-reported outcomes, including Visual Analogue Scale (VAS) for pain and Oswestry Disability Index (ODI), were assessed preoperatively and at three, six, and twelve months postoperatively. This study aims to determine whether less invasive methods, such as unilateral or stand-alone techniques, achieve clinical outcomes comparable to bilateral fixation while minimising morbidity.
By evaluating pain scores, functional improvement, and complications contextualised by existing biomechanical and radiographic data, the best option for minimising surgical morbidity and preserving future revision options will be concluded. This research seeks to refine surgical decision-making; thus, the findings may influence clinical practice by clarifying the trade-offs between procedural risks and long-term outcomes in LLIF.