Lumbar fusion surgery is a widely utilized procedure for the treatment of a variety of spinal pathologies, including degenerative disc disease, lumbar spondylolisthesis, and spinal instability. Among the surgical techniques available, transforaminal lumbar interbody fusion (TLIF) has gained prominence due to its ability to access the disc space through a posterior approach, reduce neural retraction, and allow for thorough disc removal and interbody cage placement with minimal disruption to the spinal canal.(1)
A critical factor in TLIF procedures is the type and positioning of the interbody cage. Traditionally, bilateral straight cages have been inserted to promote symmetrical load sharing and increase the surface area for fusion. This technique aims to ensure even support of the anterior column and reduce the risk of cage subsidence or pseudarthrosis. On the other hand, unilateral insertion of banana-shaped cages has been introduced as a potentially less invasive alternative that simplifies the procedure while still achieving adequate segmental stability and fusion.(2,3) Despite growing adoption of both bilateral straight and unilateral banana cages, controversy remains regarding their relative biomechanical performance, clinical efficacy, and complication profiles. Factors such as asymmetrical load distribution in unilateral constructs, differences in cage surface area contact, and potential risks for adjacent segment degeneration or cage migration have yet to be definitively resolved through high-quality comparative studies.(4,5) This study protocol aims to compare the outcomes of bilateral straight cage versus unilateral banana cage insertion in lumbar spine fusion surgery. By evaluating parameters such as fusion rate, operative time, blood loss, cage subsidence, and patient-reported outcomes, the study will provide evidence-based insights to guide surgical technique selection and improve long-term outcomes for patients undergoing lumbar spine fusion surgery .(6,7)
