Rim Lesions – Dynamic Modeling
Rim lesions of the intervertebral disc exist in outer periphery of the annulus fibrosus. Researchers have wondered if these outer disc injuries facilitate degeneration. In an article published in the European Spine Journal, Melrose et al. looked to recent advances in annular pathobiology to reveal more of the truth. Their objective was to determine the impact annular rim lesions on the etiology of disc degeneration.
As an introduction, it is well known that the disc plays a crucial role in spinal flexibility and stability to allow movement. The outer fibrous lamellae consist of alternating sheets at 35 and 55 degrees. These alternating sheets prevent rotation from occurring too much with half the fibres coming into tension when the vertebra rotate one way while the remaining go into a slackened state….similar to the plys of a bias tire.
Rim lesions are those injuries that occur around the edge of the disc, at the rim. Rim lesion was originally described by Schmorl and Junghans (1971) as discontinuities in the vertebral attachment to the annulus fibrosus that may arise from an avulsion of the annular bony attachment adjacent cartilaginous end-plate.
To get a clearer picture of what this looks like, below is an image showing a lumbar model with a potential area where a rim lesion may exit.
Dynamic Disc with Nuclear Migration – Rim Lesion
Dynamic Disc Designs include rim lesion modeling to help in the better understanding of mechanisms associated with pain and solutions to alleviate it.