Shoulder Dislocation

Shoulder Dislocation Overview

When you have the misfortune of wrenching your shoulder upward and backward, you may dislocate it out of its socket. This condition is both painful and incapacitating. The force required is often that of a fall or a collision with another person (both of which can occur with many sports).

Because of how your shoulder fits together, most shoulder dislocations happen at the lower front of the shoulder. The bones of the shoulder are the socket of the shoulder blade (scapula) and the ball at the upper end of the arm bone (humerus). The socket on the shoulder blade is fairly shallow, but a lip or rim of cartilage makes it deeper. The joint is supported on all sides by ligaments called the joint capsule, and then the whole thing is covered by the rotator cuff. The rotator cuff is made up of 4 tendons that are attached to muscles that start on the scapula and end on the upper humerus. They reinforce the shoulder joint from above, in front, and in back, which makes the weakest point in the rotator cuff in the lower front.

Subluxation versus dislocation: A subluxation occurs when 2 joint (articular) surfaces have lost their usual contact. A 50% subluxation means the normally opposing articular surfaces have lost half their usual contact. A 100% subluxation means the articular surfaces have lost all of their contact. A dislocation is the same as a 100% subluxation.

Shoulder Dislocation Symptoms

• The main symptom of a shoulder dislocation is severe pain at the shoulder joint.
  
  
• You will have great difficulty moving your arm even a little bit.
  
  
• If you touch the shoulder from the side, it feels mushy, as if the underlying humeral head is gone (usually the humeral head is displaced below and toward the front).

When to Seek Medical Care

Many doctors’ offices are not equipped to care for a shoulder dislocation. You might call the doctor to seek advice in this regard and ask which hospital is best.

If you strongly suspect you have a shoulder dislocation, you should seek emergency care. Usually this means going to an emergency department. Waiting several hours before seeking treatment could result in unnecessary suffering and further damage to tendons, muscles, blood vessels, and nerves.

Exams and Tests

After taking a history (time of injury, how it happened, prior serious health problems or injuries), the doctor may do a brief general exam followed by a more detailed exam of the injured shoulder.

• The deltoid muscle (the round muscle covering the shoulder joint) may appear to be flatter on the injured side when compared to the healthy side. Any movement of the arm may cause pain in the shoulder.
  
  
• The pulse at the wrist, touch sensation, and hand movement are usually normal. (Damage to nerves, blood vessels, ligaments, tendons, and muscles can occur. These injuries can be difficult to diagnose because you are incapacitated by the dislocation.)
• 
  
• A set of shoulder x-rays is usually standard in diagnosing a shoulder dislocation. Not only is it important to determine the presence of a dislocation, but your doctor should use it to check for other injuries that may look the same (such as a fracture of the upper humerus at its neck or tearing of the ligaments connecting the collarbone to the shoulder blade).