Anatomical and radiologic studies on the lumbosacral meningo-vertebral ligaments of humans.

Among the minor soft structures of the lumbosacral spinal canal that computed tomography can visualize, the meningovertebral ligaments have been neglected. There are no specific reports on this subject, and the only knowledge we have comes from very ancient and nearly forgotten anatomical works. From our studies on cadaveric specimens, it has been confirmed that the ligaments consist segmentally of ventral and lateral fibrous bands, connecting the outer surface of the dura to the endostium of the spinal canal. The most characteristic component is the ventral one, running from the anterior wall of the dural sac to the posterior longitudinal ligament and vertebral endostium. Due to their anchoring function, the ligaments are significantly developed at the level of the dural conus (sacrodural ligaments of Trolard and Hofmann). On in vivo computed tomography studies, the ligament image appears most commonly on transverse scanograms of the lumbosacral segments as a median sagittal septum, easily identifiable when the extradural fat that it crosses is abundant. The meningovertebral ligaments may be implicated in pathological conditions of the spinal canal. They can calcify singly, though very rarely, and this process must be differentiated from degenerative marginal spurs, calcific disc herniation, circumscribed calcification of the posterior longitudinal ligament, or partial diplomyelia.