 This retrospective comparative study investigated the effects of the lordotic angle of cages on sagittal alignment in patients who underwent one or two-level posterior lumbar interbody fusion, PLIF, including the L5-S1 level. The results revealed that clinical and radiological parameters were not different between the two groups. However, sagittal parameters did not improve postoperatively in either group. Additionally, the degree of anterior location of cages was positively correlated with the postoperative restoration of the segmental angle. Therefore, PLIF at the L5-S1 level should be used with caution as improvement in sagittal alignment did not occur. This article was authored by Jay Hwan Cho, Chang Ju Wong, Dong Lee, and others.