The clavicle and scapula are tightly linked through the strong coracoclavicular and acromioclavicular ligaments and link the axial skeleton to the upper extremity.

Clavicles are present only in brachiating animals and apparently serve to help hold the upper limb away from the trunk to enhance more global positioning and use of the limb.

The clavicle is named for its S-shaped curvature, with an apex anteromedially and an apex posterolaterally, similar to the musical symbol clavicula. The larger medial curvature widens the space for passage of neurovascular structures from the neck into the upper extremity through the costoclavicular interval.

The clavicle is made up of very dense trabecular bone lacking a well-defined medullary canal. In cross-section, the clavicle changes gradually between a flat lateral aspect, a tubular midportion, and an expanded prismatic medial end.

The clavicle is subcutaneous throughout its length and makes a prominent aesthetic contribution to the contour of the neck and upper part of the chest.

The supraclavicular nerves run obliquely across the clavicle just superior to the platysma muscle and should be identified and protected during operative exposure to offset the development of hyperesthesia or dysesthesia over the chest wall.

Clavicle fractures usually result from a direct blow to the point of the shoulder.

This is usually a moderate- to high-energy injury in younger adults but can result from a low-energy fall from a standing height in an older individual.

The overall nonunion rate for diaphyseal clavicle fractures is 4.5%.⁹

The risk of nonunion increases with age, female gender, displacement, and comminution.⁹

The risk of nonunion for completely displaced (no apposition) and comminuted fractures is between 10% and 20% (FIG 1).¹¹

Malunion of the clavicle can result in shoulder girdle deformity and weakness.^{3, 4, 6, 11}

Malunion and nonunion of the clavicle can result in brachial plexus compression.

The mechanism and date of injury should be elicited.

A careful neurologic examination should be performed.

“Tenting” of the skin by a fracture fragment is only problematic in patients who cannot protect their skin (eg, patients who are comatose).

An anteroposterior (AP) radiograph can be supplemented by a 20- to 60-degree cephalad-tilted view.

The so-called apical oblique view (tilted 45 degrees anterior and 20 degrees cephalad) may facilitate the diagnosis of minimally displaced fractures (eg, birth fractures, fractures in children).

The abduction lordotic view taken with the shoulder abducted above 135 degrees and the central ray angled 25 degrees cephalad is useful in evaluating the clavicle after internal fixation. Abduction of the shoulder results in rotation of the clavicle on its longitudinal axis, which causes the plate to rotate superiorly and thereby expose the shaft of the clavicle and the fracture site under the plate.

Computed tomography with three-dimensional (3-D) reconstructions can help understand 3-D deformity.