Impact of Cage Angle on Spinal Alignment in Posterior Lumbar Interbody Fusion: A Comparison of 12°, 16°, and 22° Cages

PLIF using high-angle cages (≥12°) significantly improved local alignment in all groups. The 22° cage showed greater improvements in SLL and SIA but a higher incidence of cage subsidence. No significant clinical differences were observed between groups. LL in the lower lumbar spine can be achieved relatively easily using a cage with a larger angle in PLIF. However, although a cage with a larger angle may be advantageous for lordosis formation, postoperative clinical outcomes do not differ; therefore, cage selection should consider the surgeon's skill and patient factors, such as the degree of preoperative lumbar disc degeneration, instability, and alignment.