= CARTILAGINOUS NODE

= superior / inferior intravertebral herniation / prolapse of disk material through weakened area of vertebral endplate

[Christian Georg Schmorl (1861–1932), pathologist at city hospital in Dresden, Germany]

Pathogenesis: disruption of cartilaginous plate of vertebral body left during regression of chorda dorsalis, ossification gaps, previous vascular channels

Cause:

1. osseous: osteoporosis, osteomalacia, Paget disease, hyperparathyroidism, infection, neoplasm
2. cartilaginous: intervertebral osteochondrosis, disk infection, juvenile kyphosis

Location: predominantly in thoracolumbar spine

• acute Schmorl nodes may be painful
• concave defects at upper and lower vertebral endplates with sharp margins

MR:

• node of similar signal intensity as disk
• low signal intensity of rim
• associated with narrowed disk space

DDx: inflammatory disease