The clavicle, or collarbone, is attached to the top of the shoulder at the acromion, through the AC joint. Injury to this joint will cause shoulder separation. The clavicle is also attached to the sternum in the middle of the body through the center clavicular joint. The sternoclavicular joint is supported by strong ligaments—the sternoclavicular and the costal clavicular ligaments. Injury to these ligaments can cause dislocation of the joint.
The clavicle will either dislocate anteriorly (to the front) or posteriorly (behind). In the event of an anterior dislocation, the end of the clavicle will stick out near the sternum, forming a bump in the middle of the chest. The presence of a bump in this area does not always mean that there is an anterior dislocation.
This abnormality can be cause due to infection, tumor, or arthritis. A CT scan may be necessary for a diagnosis. Anterior dislocations typically occur in patients with a history of trauma and pain. This dislocation is benign and direct pressure may be enough to reduce the joint. A closed reduction involves pulling, pushing, and moving the clavicle until it pops back into the joint, and this is often unsuccessful. Conservative treatment methods include the use of a sling and ice therapy. Recurrence is common and there may be a residual cosmetic deformity. Anterior dislocations are rarely symptomatic. Operative techniques are rarely utilized. A surgeon may choose a resection arthroplasty to preserve the costoclavicular ligament, or a sternoclavicular reconstruction with graft.
Posterior dislocations are dangerous because when the clavicle is sent backwards, it compresses the structures in the mediastinum. This may cause patients to have difficulty breathing and make it painful to swallow. X-rays are usually not helpful in diagnosing the problem so, the physician will want to obtain CT scans if they suspect a posterior dislocation. An urgent closed reduction is mandatory for posterior dislocations, and they often has successful and stable results. An open reduction may be required if a closed reduction is unsuccessful. In these cases, it is helpful to have a consultation with a cardiac surgeon as well.
