The epidural ligaments during fetal development.

The topography of the developing epidural ligaments in man was investigated by dissecting 12 fetuses ranging from 60-310 mm in CR length. It was found that in a 60 mm CR length fetus, the epidural space is occupied by an ubiquitous connective tissue which in longer fetuses becomes reduced into topographical structures. Posterior, lateral and anterior ligaments could be identified. The atlantodural and the sacral ligaments appear to be permanent ligaments anchoring the dural sac, whereas most of the dorsal ligaments become resorbed during the development of the fetus. These ligaments may be responsible for the compression of the nerve root that occurs when the dural sleeve and the contained nerve root are stretched over a protrusion (e.g. a protruded disc).