Elastic fibres in the anulus fibrosus of the adult human lumbar intervertebral disc. A preliminary report.

Two intervertebral discs were removed at autopsy from the lumbar region of the spine from male or female adult human cases at the following ages: 26, 34, 43, 50 and 62 years. The discs were prepared by paraffin wax embedding, sectioned serially and stained with haematoxylin and eosin or by Verhoff's elastic fibre method. Four light microscopy photomicrographs were made of randomly selected 400 micron 2 areas of anulus fibrosus matrix (two each from different levels of a single disc). Each photomicrograph was examined for elastic fibres, and the areas occupied by them were quantitated by manual planimetry. Elastic fibres were observed in all lamellae of the anulus fibrosus at lumbar levels and they were circularly, obliquely and vertically oriented. Approximately 10% of the matrix of the anulus fibrosus consisted of elastic fibres and their numbers tended to decrease slightly with increasing age of the individual.