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Limbus vertebra is a benign, developmental anomaly resulting from the herniation of the nucleus pulposus through the cartilaginous vertebral endplate beneath the ring apophysis before fusion.

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This causes a well-corticated, triangular bone fragment at the vertebral body margin, most commonly in the anterior-superior corner.

Etiopathology

It is not a fracture, though it may mimic one in trauma settings

Occurs during childhood or adolescence while the ring apophysis is still unfused
Intervertebral disc material herniates through the endplate, displacing a portion of the ossification center
Results in non-united bony fragment adjacent to the vertebral body

Epidemiology:

More common in young males
Incidental finding in many cases
Can rarely be symptomatic if posterior and causing spinal canal impingement

Location

Location	Frequency
Anterior-superior vertebral margin (most common)	>90%
Posterior margin (rare)	Potentially symptomatic due to cord or nerve root compression

Radiology

Modality	Imaging features
XR	• Triangular or rectangular bony fragment at the anterosuperior corner of the vertebral body
• Well-corticated margins, separate from the main vertebral body
• Commonly mistaken for a healed compression fracture fragment or avulsion
CT	• Best modality for bony detail
• Clearly shows corticated fragment with no signs of acute fracture
• No edema or soft tissue swelling
MR	• Shows adjacent disc degeneration (if present)
• Posterior limbus vertebra may compress the thecal sac or nerve roots
• No marrow edema in chronic lesions

https://www.youtube.com/watch?v=gdxLJ1B-e5Y

Radiography:

![A 23 year old young adult female presented with a complaint of low back ache for the past few months. (a, b) Radiograph of the lumbosacral spine reveals a wedge-shaped bony fragment in the anterosuperior corner of the L3 vertebra (arrow in b), consistent with a limbus vertebra. Multiple radiopaque calculi are also noted in a dependent fashion along a contour resembling the gallbladder fundus at the level of the L3 vertebra on the right side. Another radio-opaque calculi is seen at the L1-L2 vertebral level on the left side, likely representing a left renal calculus. Case courtesy Dr Nabarun Das sir, MD // #SMCHCase

c. Pictorial representation of marginal interosseous herniation of the nucleus pulposus in the anterosuperior border of the vertebral body.

Espino-Rodríguez César A, García-Ballesteros Alejandra I, Castro-Prado Fernando C. Incidental diagnosis of limbus vertebra associated with disc hernia in patient with low back pain: Case report. Interdisciplinary Neurosurgery. 2020;19:100617. doi:https://doi.org/10.1016/j.inat.2019.100617](attachment:e798e246-b1bf-4886-82fe-ecf8af0474f9:LV.jpg)

A 23 year old young adult female presented with a complaint of low back ache for the past few months. (a, b) Radiograph of the lumbosacral spine reveals a wedge-shaped bony fragment in the anterosuperior corner of the L3 vertebra (arrow in b), consistent with a limbus vertebra. Multiple radiopaque calculi are also noted in a dependent fashion along a contour resembling the gallbladder fundus at the level of the L3 vertebra on the right side. Another radio-opaque calculi is seen at the L1-L2 vertebral level on the left side, likely representing a left renal calculus. Case courtesy Dr Nabarun Das sir, MD // #SMCHCase

c. Pictorial representation of marginal interosseous herniation of the nucleus pulposus in the anterosuperior border of the vertebral body.