Annular tears and disc degeneration in the lumbar spine. A post-mortem study of 135 discs

Abstract

We studied 135 lumbar discs from 27 spines removed post-mortem from subjects of an average age of 31.5 years. Defects of the annulus fibrosus were classified as peripheral, circumferential or radiating; the nucleus pulposus as normal, moderately or severely degenerate. Peripheral tears were more frequent in the anterior annulus, except in the L5-S1 disc. Circumferential tears were equally disfributed between the anterior and the posterior annulus. Almost all the radiating tears were in the posterior annulus, and closely related to the presence of severe nuclear degeneration.

What is Intervertebral Disc Degeneration, and What Causes It?

“…45 Circumferential tears may represent the effects of interlaminar shear stresses, 46 possibly occurring from compressive stress concentrations in older discs ( Figure 3). Peripheral rim tears are more frequent in the anterior anulus 47 and may be associated with bony outgrowths. 48 Mechanical 4 and histologic 47 considerations suggest that they are related to trauma.…”

“…Peripheral rim tears are more frequent in the anterior anulus 47 and may be associated with bony outgrowths. 48 Mechanical 4 and histologic 47 considerations suggest that they are related to trauma. Radial fissures progress outward from the nucleus, usually posteriorly or posterolaterally, 47 and this process can be simulated in cadaveric discs by cyclic loading in bending and compression.…”

“…48 Mechanical 4 and histologic 47 considerations suggest that they are related to trauma. Radial fissures progress outward from the nucleus, usually posteriorly or posterolaterally, 47 and this process can be simulated in cadaveric discs by cyclic loading in bending and compression. 4 Radial fissures are associated with nucleus "degeneration," 47,49 but it is not clear which comes first.…”

“…Radial fissures progress outward from the nucleus, usually posteriorly or posterolaterally, 47 and this process can be simulated in cadaveric discs by cyclic loading in bending and compression. 4 Radial fissures are associated with nucleus "degeneration," 47,49 but it is not clear which comes first. The 3 types of anulus tear probably evolve independently of age and each other.…”

Morphological changes in disc herniation in the lower cervical spine: an ultrastructural study

“…The reasons for these degenerative diseases still remain unclear [2]. Other abnormal features are tears either peripheral (rim lesions) which are thought to result from trauma, or circumferential and radial tears which may be related to the presence of nuclear degeneration [3]. Some authors stated that disruption of the annulus and formation of tears during degeneration are a reason for a fragmented nucleus to protrude into the annulus fibrosus [4].…”