lumbar rib

Last reviewed 01/2018

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.