PT  - JOURNAL ARTICLE
AU  - Bakhaidar, Mohamad
AU  - Harinathan, Balaji
AU  - Devaraj, Karthik Banurekha
AU  - DeGroot, Andrew
AU  - Yoganandan, Narayan
AU  - Shabani, Saman
TI  - Comparative Biomechanical Analysis of Anterior Lumbar Interbody Fusion and Bilateral Expandable Transforaminal Lumbar Interbody Fusion Cages: A Finite Element Analysis Study
AID  - 10.14444/8630
DP  - 2024 Aug 30
TA  - International Journal of Spine Surgery
PG  - 8630
4099  - https://www.ijssurgery.com/content/early/2024/08/30/8630.short
4100  - https://www.ijssurgery.com/content/early/2024/08/30/8630.full
AB  - Background Expandable transforaminal lumbar interbody fusion (TLIF) cages could offer an alternative to anterior lumbar interbody fusion (ALIF). Bilateral cage insertion enhances endplate coverage, potentially improving stability and fusion rates and maximizing segmental lordosis. This study aims to compare the biomechanical properties of bilateral expandable TLIF cages to ALIF cages using finite element modeling.Methods We used a validated 3-dimensional finite element model of the lumbar spine. ALIF and TLIF cages were created based on available product data. Our focus was on analyzing spinal motion in the sagittal plane, evaluating forces transmitted through the vertebrae, and comparing an ALIF model with various TLIF cage models.Results The largest TLIF cage model exhibited a 407.9% increase in flexion motion and a 42.1% decrease in extension motion compared with the ALIF cage. The second largest TLIF cages resulted in more flexion motion and less extension motion compared with ALIF, while smaller cages were inferior to ALIF. ALIF cages were associated with increased adjacent segment motion compared with TLIF cages, primarily in extension. Endplate stress analysis revealed higher stress in the ALIF cage model with a more uniform stress distribution.Conclusion ALIF cages excel in stabilizing L5 to S1 during flexion, while largest TLIF cages offer superior stability in extension. Large bilateral TLIF cages may provide biomechanical stability comparable to ALIF, especially in extension and could potentially reduce the risk of adjacent segment disease with lower adjacent segment motion.Level of Evidence 5.