Shoulder dislocation and instability

Shoulder instability means the ball of the upper arm bone slips partly (subluxation) or completely (dislocation) out of the shoulder socket. It often starts with an injury. Once the shoulder has dislocated, the surrounding tissues may be stretched or torn, which can make it easier for it to happen again.

• Sudden, severe pain and an arm that cannot be moved after a dislocation
• A shoulder that feels loose or slips in certain positions
• Repeated episodes of the shoulder slipping out and back in
• Apprehension about overhead or throwing positions
• Aching and weakness between episodes

A dislocated shoulder needs to be put back in place (reduced) by a trained clinician, followed by X-rays to check for fractures. An MRI may be used to look for damage to the labrum, cartilage, or bone.

Non-operative treatment includes a short period in a sling followed by physical therapy to restore motion and strengthen the muscles that stabilize the shoulder.

Surgery may be considered when the shoulder keeps dislocating or feels unstable despite therapy, and is sometimes discussed after a first dislocation in younger, active people. Common procedures repair the torn labrum and tighten the stretched capsule, usually arthroscopically. When there is significant bone loss, a procedure that adds bone to the socket may be recommended. Recovery involves a sling and a staged rehabilitation program.