A collarbone (clavicle) can be dislocated both at the shoulder - an acromioclavicular dislocation
("separated shoulder") or much less commonly at the center of the chest (a sternoclavicular dislocation).
The ac dislocation has six types, types 1-3 are the most common. Generally, treatment is conservative, with early motion and advancing activities as tolerated. Common rugby/footbal/hockey injury.