Clavikula

Clavikula, also known as the clavicle in English, is a slender, S-shaped long bone about 15 cm long in the adult. It forms the anterior part of the shoulder girdle and connects the sternum to the scapula, acting as a strut that holds the upper limb away from the thorax and aids in transmitting forces from the arm to the axial skeleton.

The clavikula has two ends and a shaft. The medial (sternal) end articulates with the manubrium of the sternum at the sternoclavicular joint; the lateral (acromial) end articulates with the acromion of the scapula at the acromioclavicular joint. It lies just beneath the skin along the superior chest wall, making it relatively exposed to trauma.

Functionally, the clavikula helps position the scapula for a wide range of shoulder movements and serves as a lever for arm motion. Numerous muscles attach to its surfaces, including the sternocleidomastoid at the medial end, pectoralis major to the medial shaft, deltoid to the lateral third, trapezius to the acromial end, and the subclavius muscle underneath. Stabilizing ligaments include the sternoclavicular, costoclavicular, interclavicular, and acromioclavicular ligaments.

Developmentally, the clavikula begins to ossify early in gestation and exhibits a mixed ossification pattern, with secondary ossification centers appearing later in childhood or adolescence and fusing in early adulthood.

Clinically, clavicular fractures are common, especially in the middle third, due to the bone’s curvature and exposed position. They may result from falls or direct blows to the shoulder and can involve nearby structures such as vessels or the apex of the lung in severe cases. Diagnosis is typically by X-ray, with CT used for complex injuries, and management depends on fracture type, displacement, and patient age.