Biomechanical analysis of posterior, transforaminal, extreme, oblique, and anterior lumbar interbody fusion surgical models: a finite element study

Many lumbar interbody fusion methods have been proposed, but there is a relative scarcity of fundamental biomechanical research on these varied surgical procedures. In this study, a finite element model of an L4-L5 functional spinal unit was created and five interbody fusion methods were evaluated, including posterior lumbar interbody fusion (PLIF), transforaminal lumbar interbody fusion (TLIF), extreme lateral interbody fusion (XLIF), oblique lateral interbody fusion (OLIF) and anterior lumbar interbody fusion (ALIF). Static and harmonic vibration surgery analysis models were developed based on it, investigating the biomechanical properties, as well as the variation of strain energy. Results indicate that while OLIF and XLIF produced similar biomechanical outcomes, 45.8% higher facet joint contact stress in OLIF compared to XLIF. In contrast, TLIF and PLIF exhibit superior performance, with TLIF showing stress concentration on the left-side screw. ALIF outperformed other models in terms of overall stability, but has significantly higher stress peaks and sensitivity to vibration loads. In general, PLIF exhibits no significant shortcomings, TLIF offers excellent dynamic performance, OLIF and XLIF may exert greater pressure on the facet joints, and ALIF provides optimal stability. The integration of these findings into clinical practice can provide a theoretical basis for clinical surgeons when selecting surgical approaches.