Dislocation of the shoulder means the displacement of the upper arm bone (humerus) out of the shoulder joint. The shoulder joint is the most frequently dislocated major joint of the body — often caused by a significant force that separates the shoulder joint's ball (the top rounded portion of the upper arm bone, or humerus) away from the joint's socket (glenoid). The shoulder can dislocate in several ways, including the following:
Forward and downward dislocation. These are the most common types of dislocations, which are usually the result of falling on an outstretched hand or on the shoulder itself.
Backward dislocation. This type of dislocation may be caused by a direct blow to the front of the shoulder, the violent twisting of the upper arm, a seizure, or electrocution.
In addition, a shoulder can be partially dislocated (the head of the upper arm is partially out of the shoulder socket) or completely dislocated (the head of the upper arm is completely out of the shoulder socket).
A dislocation can result in a fracture of the upper arm bone. Other complications may include the following:
Damage to an artery
The following are the most common symptoms of a dislocated shoulder. However, each individual may experience symptoms differently. Symptoms may include:
Pain in the upper arm and shoulder, which is usually worse during attempts at movement
Numbness and weakness
Deformity of the shoulder (in a forward dislocation)
The symptoms of a dislocated shoulder may resemble other conditions or medical problems. Always consult a doctor for a diagnosis.
In addition to a complete medical history and physical examination, diagnostic procedures for a dislocated shoulder may include an X-ray (a diagnostic test that uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film).
Specific treatment for a shoulder dislocation will be determined by your doctor based on:
Your age, overall health, and medical history
Extent of the injury
Your tolerance for specific medications, procedures, or therapies
Expectations for the course of the injury
Your opinion or preference
Treatment may include:
Moving the head of the upper arm bone back into the shoulder joint, usually after an anesthetic
Immobilization of the shoulder with a sling
Surgery if nonsurgical measures do not restore stability