What is a dislocated shoulder?

A dislocation of the shoulder joint happens when the bones making up your shoulder joint are moved apart so that the joint no longer functions.

Your shoulder is made up of two bones: the ball (the end of the arm bone, or humerus) and the socket (part of your shoulder blade, or scapula). When the ball part of the joint is dislocated in front of the socket, it is called an anterior dislocation. When it is dislocated behind the socket, it is called a posterior dislocation. In severe cases, ligaments, tendons, and nerves also can be stretched and injured.

How does it occur?

The most common type of dislocation is an anterior dislocation. It can be caused by a fall onto your outstretched hand or onto the shoulder itself.

A posterior dislocation may occur as a result of a powerful direct blow to the front of your shoulder. It may also be caused by a violent twisting of your upper arm, such as that caused by an electric shock or seizure.

Dislocated shoulders are common in contact sports such as football, rugby, hockey, and lacrosse. Other sports that may cause the injury include downhill skiing, volleyball, and soccer.

You also may be genetically susceptible to a dislocation, particularly if your shoulder goes out often or easily. Other members of your family may have the same problem.

What are the symptoms?

The main symptom is pain in your shoulder and upper arm that is made worse by movement.

If you have an anterior dislocation, you will find yourself holding your arm on the dislocated side slightly away from your body with your opposite hand. This will keep your dislocated shoulder in the least uncomfortable position. Your shoulder will have a large bump rising up under the skin in front of your shoulder. Your shoulder will look square instead of round.

If you have a posterior dislocation, you will hold your arm on the dislocated side tight against your body. You will have a large bump on the back of your shoulder.

How is it diagnosed?

Your doctor will ask about your medical history, including your symptoms, previous treatment, and family history. During your physical exam, your doctor will check for:

• shoulder tenderness and weakness

• numbness in the shoulder area, arm, or hand

• pain when you move your shoulder or loss of normal shoulder motion

• shoulder instability and deformity.

Your doctor will arrange for an x-ray of the joint and surrounding areas to confirm the dislocation and check for broken bones.

What is the treatment?

You should go to your doctor's office or the hospital emergency room immediately when your shoulder becomes dislocated. Put ice on your shoulder. Cold reduces swelling by controlling internal bleeding and the buildup of fluids in and around the injured area.

Your doctor will reposition the head or ball of the joint back into the joint socket. This can sometimes be done without an anesthetic if it is done within a few minutes after the dislocation occurs. If you have recurrent dislocations, you may be able to learn how to put your shoulder back into place by yourself. However, even in such cases you should see a doctor promptly to make sure the repositioning has been done properly.

Fifteen to thirty minutes after the injury, your dislocated shoulder will probably be quite swollen and painful. You may then need to be given an intravenous (IV) pain medication and muscle relaxant or general anesthesia before the doctor repositions your shoulder. Sometimes local anesthetic can be injected into the joint to help the doctor reposition the bones. After the repositioning, your doctor will have your shoulder x-rayed to make sure it is in the correct position.

Your doctor will place your shoulder and arm in a type of sling called a shoulder immobilizer. It will aid healing by keeping your arm next to your body and stopping you from moving your shoulder. You will keep your shoulder and arm in the immobilizer for 2 to 3 weeks. You may begin shoulder rehabilitation exercises during this time or after you are no longer wearing the immobilizer.

Your doctor may prescribe an anti-inflammatory medication or other pain medicine. You should continue to place ice packs on your shoulder for 20 to 30 minutes every 3 to 4 hours until the pain and swelling are gone.

In some cases, surgery may be needed to get the shoulder repositioned correctly or if it continues to dislocate. If your shoulder joint becomes weak because of repeated dislocations, your doctor may recommend an operation to tighten the ligaments that hold the joint together.

How long will the effects of shoulder dislocation last?

The healing process may take 4 to 12 weeks, depending on the extent of your injury. With proper healing, you should regain full movement of your shoulder.

How can I take care of myself?

Follow your doctor's instructions when you begin to use your arm and shoulder again, or you may reinjure it. Do the rehabilitation exercises that are given to you by your doctor or therapist. Avoid participation in sports until the shoulder has had time to heal.

What can be done to help prevent a dislocated shoulder?

• Avoid situations in which you could suffer another dislocation.

• Wear layers of clothing or padding to help cushion any fall that may be likely.

• Do not return to sports until you have full recovery of motion and strength in the arm.