Unilateral vs Bilateral Pedicle Screw Fixation in Traditional and Minimally Invasive Transforaminal Lumbar Interbody Fusion: A Systematic Review of Literature of the Last 10 Years (2022-2012)

Introduction: Value-based care and its principles of cost-efficiency have been applied to minimally invasive spine surgery in recent years. One area of interest is in comparing unilateral and bilateral pedicle screw fixation (uni-TLIF and bi-TLIF respectively) in both traditional and minimally invasive transforaminal lumbar interbody fusions (mi-TLIFs) for treatment of lumbar degenerative disk disease (LDD).

Methods: The authors performed a PRISMA guidelines-based systematic review of the literature, comparing outcomes of unilateral and bilateral pedicle screw fixation in traditional open and mi-TLIFs, from 2012-2022, with at least 1 year follow up.

Results: The search strategy yielded 392 publications, of which 11 were included. 2 studies were retrospective cohort studies and 9 were prospective cohort studies. 4 studies focused on mi-TLIFs. All studies, regardless of intervention or indication specifics, related shorter operative times and blood loss volume for the unilateral group compared to the bilateral. The majority of studies that gathered data on length of stay demonstrated shorter lengths for patients who received unilateral instrumentation. Of studies including cost, unilateral instrumentation proved significantly less expensive. Most studies found no difference in back pain or disability measures between uni-TLIF and bi-TLIF.

Conclusion : Unilateral instrumentation in TLIFs may provide an equally effective, less expensive, less invasive option for patients with LDD, with minimal operative time, blood loss. Cost savings seen with uni-TLIF compared to bi-TLIF are significant and should be considered strongly. Therefore, unilateral instrumentation in both traditional and mi-TLIF seems to be a comparably advantageous intervention for carefully selected patient populations.