Adhesions of the ventral lumbar dura. An adjunct source of discogenic pain?

An analysis of the frequencies and locations of lumbar ventral dural adhesions was undertaken to ascertain their possible role in enhancing the low-back pain consequent to lumbar disc herniation. Data derived from a previous investigation, conducted for a different purpose, were incorporated with that of the presented study to provide a more extensive statistical base. Adhesions judged sufficient to possibly cause additional nerve disruption on separation were found in 16% of the specimens at the L3-4 level; 40% at the L4-5 level; and 36% at the L5-S1 level. Dural tissue segments, taken from the forcefully separated more firmly fixed adhesions found only at the L4-5 level, microscopically showed disruption of neurovascular bundles containing branches of the sinuvertebral nerve where they coursed between the adherent dura and the posterior longitudinal ligament. It was assumed that forced separation of adhesions during disc protrusion could add to perceived discomfort.