Rib 1 (left) — true rib

Function

The shortest, widest and most curved rib. It forms the flat roof of the thoracic inlet, bracing the dome of the lung and giving purchase to the scalene muscles that bend the neck.

Landmarks

• Scalene tubercle
• Groove for the subclavian artery
• Groove for the subclavian vein

Articulations (joints)

• T1 vertebral body
• Manubrium via first costal cartilage

Clinical relevance

First-rib fractures imply extreme violence and companion injuries — subclavian vessel or brachial plexus damage. The rib is also removed in thoracic outlet decompression surgery.