A dislocated shoulder is an injury in which your upper arm bone pops out of the cup-shaped socket that's part of your shoulder blade. A dislocated shoulder is a more extensive injury than a separated shoulder, which involves damage to ligaments of the joint where the top of your shoulder blade meets the end of your collarbone.
If you suspect a dislocated shoulder, seek prompt medical attention. Most people regain full shoulder function within a few weeks after experiencing a dislocated shoulder. However, once you've had a dislocated shoulder your joint may become unstable and be prone to repeat dislocations.