Bifid rib

A bifid rib or bifurcated rib or sternum bifidum is a congenital abnormality occurring in about 1.2% of the population. Bifid ribs occur in up to 8.4% of Samoans (McKinley & O'Loughlin, p. 214). The sternal end of the rib is cleaved into two. It is usually unilateral.

Bifid ribs are usually asymptomatic, and are often discovered incidentally by chest x-ray. Effects of this neuroskeletal anomaly can include respiratory difficulties, neurological difficulties, limitations, and limited energy from the stress of needing to compensate for the neurophysiological difficulties.

This bifid rib was found incidentally on CT chest. Bifid ribs are not uncommon, more frequently unilateral. Usually asymptomatic, they may cause musculoskeletal pain or intercostal nerve entrapment. If of the 1st rib, then may be an uncommon cause of thoracic outlet syndrome. Bifid ribs are also seen in Gorlin (nevoid basal cell carcinoma) syndrome.