The lumbar anterior epidural cavity: the posterior longitudinal ligament, the anterior ligaments of the dura mater and the anterior internal vertebral venous plexus.

The contents of the anterior epidural cavity were studied to elucidate the relationship between veins, ligaments, and membranous formations. Anatomical, radiological and histological studies on human specimens after latex or gelatin/gadolinium venous injection at the level of the lumbar spine show that the posterior longitudinal ligament is a cross-shaped formation which includes the septum, the superficial part extending into the intervertebral foramen and the anterior ligaments of the dura mater. The anterior epidural cavity contains two medial and two lateral spaces. The two medial cavities enclose anterior and medial venous plexuses, which together receive the basivertebral veins; the two lateral cavities receive the anterior longitudinal veins. Contents of the medial and lateral cavities pass freely between the two. The lateral cavity connects with the intervertebral canal and dorsally into the posterior epidural space.