Schmorl nodes (correctly spelled Schmörl nodes) refer to protrusions of the cartilage of the intervertebral disc through the vertebral body endplate and into the adjacent vertebra. The protrusions may contact the marrow of the vertebra, leading to inflammation.
It is believed that Schmorl's nodes develop following back trauma, although this is incompletely understood. A more recent study suggest nucleus pulposus pressure on the weakest part of the end plate of vertebral development process during early life as possible explanation 7.
They may or may not be symptomatic, and their etiological significance for back pain is controversial. Schmorl's nodes are found in 40-75% of autopsies.
In the acute stage, Schmörl's nodes can be difficult to diagnose or detect due to sclerosis around the margin of the herniation not having had time to develop.
Schmorl nodes are among the diagnostic criteria of Scheuermann disease 6.
A limbus vertebra is closely related to a Schmorl node as well.
It is named after Christian Georg Schmörl (1861-1932), German pathologist which first described them in 1927.