Fig. 1From: Cervical sagittal alignment in adolescent high dysplastic developmental spondylolisthesis: how does the cervical spine respond to the reduction of spondylolisthesis?Measurement of the S1 upper endplate and Dub-LSA. In the left image, AB represents the upper endplate of S1 with a doming change; in the right image, α represents Dub-LSABack to article page