Prolapsed intervertebral disc
In the spinal column, the intervertebral discs act like little shock absorbers between the individual vertebrae, performing a buffer function by absorbing shocks and impacts. They are made up of a soft, gelatinous core and an outer ring of fibre that provides the stability needed. Following long-term incorrect or excessive strain, intervertebral disc prolapse can often occur. In this situation, the gelatinous core presses the outer fibrous ring against the posterior longitudinal ligament which separates the intervertebral discs from the spinal cord canal.
As a result, the pressure on the nerves of the spinal cord increases. When a disc prolapses, the fibrous ring tears and the gelatinous core leaks out. In very severe cases, the posterior longitudinal ligament can even tear and parts of the intervertebral disc core can leak into the spinal cord canal. This is what we call a "sequestrated (prolapsed intervertebral) disc".