Abstract
Twenty-nine herniated lumbar disc fragments from patients over 60 years old were pathohistologically studied. For the comparison, 109 disc fragments from patients under 59 years of age were also observed. They were classified into 7 types according to their composition. In 80% of the patients over 65, fragments were composed of annulus fibrosus (AF) and cartilaginous end plate (EP) (sometimes also with bone). The interconnections between EP and the vertebral body are weak, but collagen fibers of AF anchor it firmly to EP. As degeneration progresses, EP separates from the vertebral body and AF becomes fissured. We suppose that EP avulsed from the vertebral body and herniated with AF (sometimes accompanying a part of the vertebral body). This type can be found more than herniation of the nucleus pulposus (NP) in patients over 30, and probably appears typically in elderly patients because of the advanced degeneration of their discs.
