Comparison of the Susceptibility to Implant Failure in the Lateral, Posterior, and Transforaminal Lumbar Interbody Fusion: A Finite Element Analysis

There are several techniques for lumbar interbody fusion, and implant failure following lumbar interbody fusion can be troublesome. This study aimed to compare the stress in posterior implant and peri-screw vertebral bodies among lateral lumbar interbody fusion (LLIF), posterior lumbar interbody fusion (PLIF), and transforaminal lumbar interbody fusion (TLIF) and to select the technique that is least likely to cause implant failure. We created an intact L3–L5 model and simulated the LLIF, PLIF, and TLIF techniques at L4–L5 using finite element methods. All models at the lower portion of L5 were fixed and imposed a preload of 400 N and a moment of 7.5 Nm on the upper portion of L3 to simulate flexion, extension, lateral bending, and axial rotation. We investigated the peak stresses and stress concentration in the posterior implant and peri-screw vertebral bodies for the LLIF, PLIF, and TLIF techniques. The extension, flexion, bending, and rotation peak stresses and stress concentration in the posterior implant, as well as the peri-screw vertebral bodies, were the lowest in LLIF, followed by PLIF and TLIF. It was found that implant failure was least likely to occur in LLIF, followed by PLIF and TLIF. Hence, surgeons should be aware of these factors when selecting an appropriate surgical technique and be careful for implant failure during postoperative follow-up.