The radiate sternocostal ligament (also called the stellate ligament) is a fan-shaped fibrous band radiating from the sternal end of each costal cartilage to the anterior surface of the sternum, covering both the body and the adjacent margins. The fibres of adjacent radiate ligaments interlace across the front of the sternum to form a dense fibrous membrane reinforcing the anterior thoracic cage.
Reinforces the anterior sternocostal joint capsules, resists separation of the costal cartilages from the sternum during rib cage loading, and together with the intraarticular sternocostal ligament maintains the sternocostal articulation during respiration.
The radiate sternocostal ligaments form the tough anterior fibrous layer of the sternum that must be identified during chest wall procedures. They are disrupted in costochondritis and Tietze syndrome where inflammation at the sternocostal junction produces localised tenderness and swelling of the costal cartilage. Sternocostal dislocation, though rare, involves failure of these ligaments. Understanding their fan-shaped reinforcement pattern explains the firm anterior wall of the mediastinum encountered during median sternotomy.
Non-suppurative inflammation of the upper costal cartilages and their sternocostal ligaments, producing painful localised swelling and tenderness at the sternocostal junction, most common at the second and third costal cartilages, managed with anti-inflammatories and local anaesthetic injection.
Traumatic disruption of the radiate and intraarticular sternocostal ligaments from blunt chest trauma allows the costal cartilage to displace, producing localised pain and a palpable step, usually managed conservatively but occasionally requiring surgical stabilisation.
