clavicular

Clavicular refers to the clavicle, the slender, S-shaped bone that connects the upper limb to the axial skeleton and forms part of the shoulder girdle. The clavicle runs horizontally across the upper chest, lying just above the first rib and the lung apex.

Anatomy and joints: The clavicle has a sternal end that articulates with the manubrium of the sternum at the sternoclavicular joint and an acromial end that meets the acromion of the scapula at the acromioclavicular joint. It serves as a bridge between the upper limb and the trunk, and its position helps suspend the scapula and arm, facilitating a wide range of shoulder movements.

Function and significance: The clavicle acts as a strut that keeps the shoulder blade away from the thorax, enabling arm elevation and mobility. It transmits forces from the upper limb to the axial skeleton and protects underlying neurovascular structures as they pass from the neck to the upper limb.

Development and variation: The clavicle largely ossifies via intramembranous bone formation, with a primary center in the shaft and secondary centers at the ends that appear in adolescence and fuse in early adulthood. Variations in size, shape, or curvature occur among individuals, and rare congenital abnormalities can affect clavicular development.

Clinical relevance: Clavicular injuries, especially fractures, are common and often occur from falls or direct trauma to the shoulder. Most midshaft fractures are managed nonoperatively with immobilization, while severely displaced fractures or those with complication risk may require surgical intervention. Diagnosis typically relies on physical examination and radiographs, with additional imaging as needed to assess associated injuries.

See also: sternoclavicular joint, acromioclavicular joint.