<unk>  are fairly common, especially with minor degeneration of the aging spine, but they are also seen in younger spines.<unk>  often cause no symptoms, but may simply reflect that "wear and tear" of the spine has occurred over time; they may also reflect that bone strength was at one time somewhat compromised, perhaps due to a vitamin D deficiency although this has yet to be confirmed with studies, or if heavy lifting is done at a young age before the vertebral bodies are completely ossified such as in young farm workers. There is also a strong heritability of<unk>  (>70%). While often non-complicating,<unk>  also tend to occur more often in cases of spinal deformity, specifically Scheuermann's disease. These defects are caused when the vertebra loses its normal function and is not moving/hypomobile/subluxated. During this time the forces normally distributed by the nucleus pulposus (the incompressible gelatinous center of the intervertebral disc) are concentrated in a certain area causing endplates to deform in a concave manner.
Schmorl's nodes
Bouchard's nodes
Heberden's node
Koeppe's nodules
Bergmeister's papilla
Osler's node
Roth's spot
Bjerrum's area