Do expandable cage size and number of cages matter in transforaminal lumbar interbody fusion at L5-S1? A comparative biomechanical analysis using finite element modeling.

The authors' study shows that using a large unilateral TLIF cage may offer better stability than the bilateral insertion of smaller cages. While large bilateral cages increase adjacent-segment motion, they also provide a uniform stress distribution on the endplates. These findings deepen our understanding of the biomechanics of the available expandable TLIF cages.