Avascular necrosis of the shoulder is a serious condition. It can result from injury, the side effects of some drugs, or disease. To find out more, take a look below.

 

The Shoulder

In order to understand this condition, we need to first look at the shoulder joint.

  • Your shoulder allows you to rotate your arm, raise it and extend it forward and backward.
  • It’s made up of three bones: the bone of the upper arm (humerus), the shoulder blade (scapula), and the collarbone (clavicle).
  • The head (or ball) of the upper arm bone fits into the shallow socket in the shoulder blade. This type of joint is referred to as a ball-and-socket

 

Avascular Necrosis (AVN)  of the Shoulder

  • Avascular necrosis (also referred to as aseptic necrosis and osteonecros) of the shoulder is the second most common joint site for AVN, (the hip is the most common).
  • Avascular refers to the loss of blood supply.
  • Necrosis refers a region of bone that has died as the result of the loss of its blood supply.
  • When the blood supply to the head of the humerus is damaged, the bone dies. With living bone, the cells are constantly being repaired and renewed. Without oxygen and nutrients from circulating blood, the bone cannot survive. It begins to weaken, and eventually collapse.
  • When Avascular Necrosis AVN occurs in the shoulder joint, the head of the humerus (the ball) collapses and begins to flatten. This results in the ball no longer fitting perfectly inside the socket.

Causes of Avascular Necrosis of the Shoulder

There are a variety of causes including:

  •  Corticosteroids

This is the most common cause. These drugs are prescribed to treat a variety of illnesses. However, prolonged use can have side effects. The cells which make bone in the humeral head can be damaged as a result of these drugs and deprived of blood leading to AVN.

  • Trauma

People who have a fracture of the ball part of the shoulder are at risk of AVN. With this type of fracture, the blood supply can be disrupted leading to bone death. The more extensive the fracture the more likely it is that AVN will develop.

  • Excessive alcohol consumption

Excessive alcohol consumption causes damage to blood vessels which can result in poor blood circulation.

  • Certain diseases

Some diseases such as Sickle Cell Anemia, Lupus, Pancreatitis, Gaucher’s disease, and Caisson disease (also known as diver’s disease or the bends. A sudden change in water pressure in deep sea diving causes nitrogen bubbles to form in the blood and damage the blood supply to the humeral head).

  • Radiation or chemotherapy treatment for cancer.
  • Idiopathic (unknown).

 

Symptoms

Symptoms of avascular necrosis can vary but include the following:

  • Initially, shoulder pain is mild and occurs gradually.
  • Pain may be present or get worse with activity.
  • As the condition progresses, you may experience pain at night and when you are at rest.
  • If you have suffered a shoulder injury or fracture, you will feel pain as a result. However, if the fracture has healed but there is still persistent shoulder pain, it may be due to AVN developing. With a fracture, the blood supply can be disrupted. If pain continues after the fracture has mended, it is important to speak to your doctor.
  • The range of motion, the amount of movement in your shoulder, can begin to be restricted. In the early stages, there may be no limitation in movement, though pain may limit how much you use your arm and shoulder.
  • With movement, there may be noise and a crunching sensation (crepitation) in the shoulder. The shoulder may also lock.

Diagnosis

In the early stages, AVN may not be apparent on a plain x-ray. However, it can be seen on an MRI scan.

As the condition progresses, the bone degenerates leading to collapse of the humeral head and eventually to arthritis.

If you have shoulder problems, you may have recognized some of the above symptoms. In that case, you should see your doctor as soon as possible. Early treatment can slow the progress of avascular necrosis of the shoulder.

You Might Also Like: