coracoid

The coracoid, in humans usually referred to as the coracoid process, is a hook- or beak-shaped projection on the scapula that serves as an important anatomical landmark and attachment site. It lies at the anterosuperior aspect of the shoulder blade near the glenoid cavity and contributes to the shoulder girdle’s complex architecture.

In terms of attachments, the coracoid process provides origins for several muscles and points of ligamentous attachment. The pectoralis minor inserts on the coracoid, while the coracobrachialis and the short head of the biceps brachii originate there. The coracoid also serves as the attachment site for the coracoclavicular ligaments (conoid and trapezoid), which connect the coracoid to the clavicle, and the coracoacromial ligament, which forms part of the coracoacromial arch that helps protect the glenohumeral joint.

Across species, the coracoid can vary in structure and significance. In humans it is a process of the scapula. In many birds and some reptiles, the coracoid is a separate bone that forms a major component of the pectoral girdle, linking the sternum with the scapula and aiding wing mechanics. In fossil tetrapods, the coracoid was often a prominent, distinct element of the pectoral girdle.

Clinically, fractures or avulsions of the coracoid process are recognized shoulder injuries, though relatively uncommon. They may result from direct trauma or traction from attached muscles. Diagnosis typically involves radiography or CT, and treatment depends on fracture displacement and associated injuries, ranging from conservative immobilization to surgical fixation when necessary.