Dislocations are joint injuries that force the ends of your bones out of position. The cause is often a fall or a blow, sometimes from playing a contact sport. You can dislocate your ankles, knees, shoulders, hips, elbows and jaw. You can also dislocate your finger and toe joints. Dislocated joints often are swollen, very painful and visibly out of place. You may not be able to move it.
A dislocated joint is an emergency. If you have one, seek medical attention. Treatment depends on which joint you dislocate and the severity of the injury. It might include manipulations to reposition your bones, medicine, a splint or sling, and rehabilitation. When properly repositioned, a joint will usually function and move normally again in a few weeks. Once you dislocate a shoulder or kneecap, you are more likely to dislocate it again. Wearing protective gear during sports may help prevent dislocations.
Your shoulder joint is composed of three bones: the clavicle (collarbone), the scapula (shoulder blade), and the humerus (upper arm bone). Your shoulders are the most movable joints in your body. They can also be unstable because the ball of the upper arm is larger than the shoulder socket that holds it. To remain in a stable or normal position, the shoulder must be anchored by muscles, tendons, and ligaments.
Because your shoulder can be unstable, it can be easily injured. Common problems include
Health care providers diagnose shoulder problems by using your medical history, a physical exam, and imaging tests.
Often, the first treatment for shoulder problems is RICE. This stands for Rest, Ice, Compression, and Elevation. Other treatments include exercise and medicines to reduce pain and swelling. If those don’t work, you may need surgery.
NIH: National Institute of Arthritis and Musculoskeletal and Skin Diseases