A shoulder separation is actually an injury involving the AC (acromioclavicular) joint. This joint is where the clavicle connects with the highest point of the shoulder blade (acromion).
Deformation around the end of the clavicle, which will appear as a bulge due to the separation of the acromion and the downward shift of this bone, is the most noticeable symptom of this injury.
Immobilization, to allow the ligaments of the joint to adequately heal, is the most common treatment. The deformation caused by the separation may never return to normal, however. In severe cases, surgical intervention followed by physical therapy may be required in order to strengthen the ligaments of the AC joint and restore range of motion and stability.