Light Microscopic Study of The Lumbar Intervertebral Disc Showing Inherent Difference Between Anterior & Posterior Annulus Fibrosus - A Risk Factor For Posterior Disc Herniation.

ABSTRACT

The present study is based upon the light microscopic observations made on the foetuses to determine the structural discrepancy in anterior and posterior annulus fibrosus in the development of human foetal lumbar intervertebral disc. A morphological comparison of the structure of anterior and posterior annulus fibrosus was made to consider the arrangement of lamellar bundles. As the foetus advances in age, the anterior annulus fibrosus becomes thicker than the posterior annulus. A very intricate structure was observed in posterior annulus with large number of loose and discontinuous lamellar bundles and more fibre-interlacing angles. Loose connection of the lamellar bundles in posterior annulus of almost all the foetuses indicates an inherent weakness which may lead to posterior rupture of the disc in later life.