Cervical rib

A cervical rib in humans is a supernumerary (or extra) rib which arises from the seventh cervical vertebra. Sometimes known as "neck ribs", their presence is a congenital abnormality located above the normal first rib. A cervical rib is estimated to occur in 0.6% (1 in 150 people) to 0.8% of the population. Individuals may have a cervical rib on the right, left or both sides.