What is it about ?
The shoulder joint is formed by the arm bone (humerus) and the scapula (scapula). Shoulder dislocation is the displacement of the head of the humerus relative to the scapula cavity (glenoid cavity). The head may come out of the scapula cavity partly (subluxation) or totally (dislocation).
Bones, muscles, ligaments, cartilage, blood vessels, and surrounding nerves can be damaged. Usually a shoulder dislocation is caused by trauma, such as a fall on the arm or shoulder. Sometimes a strong blow to the shoulder, stopped movement (for example, a basketball throw), or loose joints (hyperlaxity) are the cause of the problem.
In whom and how often does it occur?
A forward shoulder dislocation (anterointernal dislocation) is the most common form of dislocation. In this case, the head of the humerus comes out of the scapula cavity and pulls forward. It happens that the humerus dislocates backwards (posterior dislocation of the shoulder) or even up or down. A dislocation rarely causes damage to blood vessels or nerves.
If you’ve ever dislocated your shoulder in the past, you’re more likely to dislocate yourself again.
How to recognize it?
You are in great pain and you cannot move your shoulder, or in a very limited way. Sometimes a bump is observed: this is the head of the humerus that has come out of the cavity of the scapula. In the event of an antero-internal dislocation, the lump is visible at the front of the shoulder and the arm is turned slightly outward. In the case of a rear dislocation, the lump is located at the back and the arm is turned slightly inward.
In addition, swelling that appears quickly, numbness in the shoulder and / or arm, loss of strength, and / or skin discoloration may also indicate shoulder dislocation.
How is the diagnosis made?
The doctor will ask you how the complaints started and he will examine your shoulder. He will especially check if there is pressure on the blood vessels or nerves. To find out, your doctor will take your wrist pulse and check if you still have tenderness in your forearm and if you can move it. If he suspects a dislocated shoulder, he will refer you to a specialist. An x-ray is usually done to confirm the diagnosis, rule out possible fractures, and determine what type of dislocation it is.
What can you do ?
If you think you have dislocated your shoulder, contact a doctor right away. A dislocation indeed needs to be treated urgently. In the meantime, you can put ice in a hand towel and apply it to the shoulder to relieve pain and deflate the area.
What can your doctor do?
Repositioning of the head of the shoulder in the scapula cavity is usually done in the hospital. Sometimes a mild anesthetic is given to relax the muscles around the shoulder and make it easier to put back in place. In certain situations, it may be necessary to reposition the shoulder surgically (i.e. under general anesthesia), for example when the dislocation has been present for a long time or after repeated dislocations.
After repositioning, the pain decreases significantly. During successful repositioning, the doctor may feel that the humerus is relocating well into the scapula cavity. To be on the safe side, an x-ray of the shoulder should always be taken before leaving the hospital. After hospitalization, the arm should be supported with a sling for 1 to 3 weeks.
A follow-up consultation with a specialist doctor (orthopedist) is sometimes necessary. Finally, you will be referred to a physiotherapist for specific exercise sessions intended to strengthen the muscles around the shoulder.
Want to know more?
- Radiography, here, Where to find on this page of Cliniques St Luc UCL
- Ultrasound here Where to find on this page of Cliniques St Luc UCL
- Scanner (CT-scan) – Erasme Hospital
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