- A cervical rib is a congenital anomaly where an extra rib arises from the seventh cervical vertebra (C7). It is present in about 0.5–1% of the population, but many individuals are asymptomatic.
- The extra rib can compress surrounding structures, including:
- Subclavian artery → Arterial insufficiency.
- Subclavian vein → Venous compression or thrombosis (e.g., Paget-Schroetter Syndrome).
- Brachial plexus → Neurological symptoms due to nerve irritation or compression.
- This compression contributes to Thoracic Outlet Syndrome (TOS), a condition causing neurovascular symptoms in the upper limb.