Reply to the Letter to the Editor of Jin Yang et al. concerning “Correlations between sedimentation sign, dural sac cross-sectional area, and clinical symptoms of degenerative lumbar spinal stenosis” by Sangbong Ko (Eur Spine J [2018] 27: 1623–1628)

[摘要] The question raised in the Letter to the Editor is justifed, and we completely agree with the authors.