The ligamentum flavum (lf) is a paired quadrangular structure with a metameric disposition, seen in dorsal view (a), dorsolateral view (b), and ventral views (c, d). The left and right ligamenta flava tend to fuse in the middle, but a gap may persist at some vertebral levels, as represented in this 3D model (arrow, c). This ligament is attached cranially to the inner surface of the vertebral lamina (vl) of the contiguous superior vertebra, as well as to the outer surface of the lamina from the contiguous inferior vertebra. It occupies the interlaminar space and keeps close relationships with the posterior epidural fat (pef), the dural sac (ds), and the zygapophyseal joint (zj) (d). To demonstrate its characteristic spatial orientation and anatomical relations, a partial transparent effect has been applied to the L3 vertebra in (a, b). The posterior vertebral arch is shown by cutting the model through the vertebral pedicles (vp), and a T2-weighted axial image (a–c) or a T1-weighted axial image (d) is used as reference. L4 L4 vertebra, ss subarachnoid space