The coracoclavicular ligaments consist of the conoid ligament (posterior and medial, cone-shaped, primary restraint against superior clavicular displacement) and the trapezoid ligament (anterior and lateral, quadrilateral, primary restraint against axial compression and posterior clavicular displacement). Together they suspend the entire weight of the upper limb from the clavicle through the coracoid process, transmitting forces from the scapula to the clavicle and ultimately to the axial skeleton.
| Origin | Coracoid process of the scapula |
|---|---|
| Insertion | Inferior clavicle (conoid tubercle for the conoid ligament; trapezoid line for the trapezoid ligament) |
| Actions | Primary vertical stabilisers of the acromioclavicular joint — suspend the scapula from the clavicle; limit clavicular rotation and scapular superior displacement |
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AC joint separations are classified by the coracoclavicular distance: Rockwood Grade I and II have intact coracoclavicular ligaments with only AC ligament disruption, while Grades III through VI involve complete coracoclavicular ligament disruption with increasing clavicular displacement. Surgical reconstruction for Grades IV through VI uses a graft (gracilis or semitendinosus) routed through the coracoid to reconstruct the conoid and trapezoid ligament geometry.
Complete CC ligament disruption in Grade III to VI AC separation producing superior clavicular displacement measured by the coracoclavicular distance on radiograph, requiring surgical reconstruction for high-grade injuries.
