A lumbar rib is an abnormality of costal development resulting in the formation of a rib or ribs that articulate with:
- the first lumbar vertebra or
- the tip of the transverse process of the first lumbar vertebra
Relatively more common than cervical rib, it is clinically important because:
- on lumbar radiogram, it may be misinterpreted as a fracture of the L1 transverse process
- it may confuse the appreciation of target organs during surgery
However, clinically it is usually silent.
Last reviewed 01/2018