Clavicle fractures account for approximately 2.6% of all fractures and for 44% to 66% of fractures about the shoulder.

Middle third fractures account for 80% of all clavicle fractures, whereas fractures of the lateral and medial third of the clavicle account for 15% and 5%, respectively.

The clavicle is the first bone to ossify (fifth week of gestation) and the last ossification center (sternal end) to fuse, at 22 to 25 years of age.

The clavicle is S-shaped, with the medial end convex forward and the lateral end concave forward.

It is widest at its medial end and thins laterally.

The medial and lateral ends have flat expanses that are linked by a tubular middle, which has sparse medullary bone.

The clavicle functions as a strut, bracing the shoulder from the trunk and allowing the shoulder to function at optimal strength.

The medial one-third protects the brachial plexus, the subclavian and axillary vessels, and the superior lung. It is strongest in axial load.

The junction between the two cross-sectional configurations occurs in the middle third and constitutes a vulnerable area to fracture, especially with axial loading. Moreover, the middle third lacks reinforcement by muscles or ligaments distal to the subclavius insertion, resulting in additional vulnerability.

The distal clavicle contains the coracoclavicular ligaments.

Falls onto the affected shoulder leading to a bending force account for most (87%) of clavicular fractures, with direct impact accounting for only 7% and falls onto an outstretched hand accounting for 6%.

Although rare, clavicle fractures can occur secondary to muscle contractions during seizures or secondary to minimal trauma due to pathologic bone or as stress fractures.

Patients usually present with splinting of the affected extremity, with the arm adducted across the chest and supported by the contralateral hand to unload the injured shoulder.

A careful neurovascular examination is necessary to assess the integrity of neural and vascular elements lying posterior to the clavicle.

The proximal fracture end is usually prominent and may tent the skin. Assessment of skin integrity is essential to rule out open fracture.

The chest should be auscultated for symmetric breath sounds. Tachypnea may be present as a result of pain with inspiratory effort; this should not be confused with diminished breath sounds, which may be present from an ipsilateral pneumothorax caused by an apical lung injury.

Up to 9% of patients with clavicle fractures have additional fractures, most commonly rib fractures.

Most brachial plexus injuries are associated with proximal third clavicle fractures (traction injury).

The skin is often abraded as a result of the injury mechanism.

Standard anteroposterior radiographs are generally sufficient to confirm the presence of a clavicle fracture and the degree of fracture displacement.

A 30-degree cephalad tilt view provides an image without the overlap of the thoracic anatomy.

An apical oblique view can be helpful in diagnosing minimally displaced fractures, especially in children. This view is taken with the involved shoulder angled 45 degrees toward the x-ray source, which is angled 20 degrees cephalad.

A chest x-ray allows for side-to-side comparison, including normal length.

Computed tomography may be useful, especially in proximal third fractures, to differentiate sternoclavicular dislocation from epiphyseal injury, or distal third fractures, to identify articular involvement.