The mildly sprained sternoclavicular joint is stable but painful.

The moderately sprained joint may be slightly subluxated anteriorly or posteriorly and may often be reduced by drawing the shoulders backward as if reducing and holding a fracture of the clavicle.

Although most anterior dislocations are unstable after closed reduction, we still recommend an attempt to reduce the dislocation closed.

Occasionally, the clavicle remains reduced, but typically, the clavicle remains unstable after closed reduction. We usually accept the deformity because an anteriorly dislocated sternoclavicular joint typically becomes asymptomatic, and we believe that the deformity is less of a problem than the potential complications of operative fixation.

When the entire medial clavicle is stripped out of the deltotrapezial fascia, the deformity can be so severe that it may be poorly tolerated, so we consider primary fixation. In those rare cases when a chronic anterior dislocation is symptomatic, one may perform a capsular reconstruction or a medial clavicle resection and costoclavicular ligament reconstruction.

In contrast to anterior dislocations, the complications of an unreduced posterior dislocation are numerous: thoracic outlet syndrome, vascular compromise, and erosion of the medial clavicle into any of the vital structures that lie posterior to the sternoclavicular joint.

Closed reduction for acute posterior sternoclavicular dislocation can usually be obtained, and the reduction is generally stable. Often, general anesthesia is necessary. However, when a posterior dislocation is irreducible or the reduction is unstable, an open reduction should be performed.

When chronic posterior dislocation is present, late complications may arise from mediastinal impingement, so we recommend medial clavicle resection and ligament reconstruction.

The typical history for physeal injuries is the same as for other traumatic dislocations. The difference between these
injuries and pure dislocations is that most of these injuries will heal with time, without surgical intervention.

In very young patients, the remodeling process can eliminate deformity because of the osteogenic potential of an intact periosteal tube. Zaslav et al,³⁹ Rockwood and Wirth,²⁹ and Hsu et al¹⁹ have all reported successful treatment of displaced medial clavicle physeal injury in adolescents and provided radiographic evidence of remodeling.

Anterior physeal injuries may be reduced, but if reduction cannot be obtained, they can be left alone without problem. Posterior physeal injuries should likewise undergo an attempt at reduction. If a posterior dislocation cannot be reduced closed and the patient is having no significant symptoms, the displacement can be observed while remodeling occurs. Even in older individuals, a posteriorly displaced fracture with moderate displacement and no mediastinal symptoms may be observed, as it usually becomes asymptomatic with fracture healing.

However, as with severely displaced dislocations, one may wish to consider operative repair for severely displaced physeal fractures. Suture repair through the medial shaft and the epiphysis and Balser plate fixation have both been successfully used in this situation.¹⁶,³⁴,³⁶

The absence of such a history suggests either an atraumatic instability or some other atraumatic condition of the joint.

Occasionally, routine anteroposterior chest radiographs suggest displacement compared with the normal side. However, these are difficult to interpret.

Serendipity view: A 45-degree cephalic tilt view is the most useful and reproducible plain radiograph for the sternoclavicular joint. The tube is centered directly on the sternum and a nongrid 11 × 14 cassette is placed on the table under the patient’s upper shoulders and neck, so the beam will project the medial half of both clavicles onto the film (FIG 3). The technique is the same as a posteroanterior view of the chest.