Avascular necrosis

This page explains about the causes, symptoms and treatment of avascular necrosis, from Great Ormond Street Hospital.

There are lots of possible reasons for developing avascular necrosis but in the vast majority of cases, it’s impossible to pinpoint a precise cause. It’s usually a condition that simply develops out of the blue.

Unfortunately, there isn’t a straightforward cure and it can sometimes linger for up to 18 months. But there is treatment available that will help your child feel more comfortable.

Avascular necrosis happens when the blood supply to the end of a bone is disrupted – either on a temporary or permanent basis.

Without a supply of blood, the affected bone and the tissue that surrounds it can gradually begin to die. This can cause the bone itself to change shape which is partly responsible for the joint stiffness that people often experience.

Avascular necrosis most often affects the top of the thigh bone (femur) but it can affect other bones too – like the elbow.

Sometimes the condition doesn’t cause any symptoms at all. But for others it can be linked with pain and/or a loss of range of movement in the affected joint.

There are many possible reasons for the blood supply to be disrupted in this way.

Sometimes, it can be linked to an injury such as a particularly bad fracture of the elbow or a difficult elbow infection.

It can be as a result of steroid treatment which is needed, for example, in the management of cancer conditions or asthma, or it can be due to sickle cell anaemia.

But in most cases it is difficult to establish a clear cause.

The condition is diagnosed by x-ray. A child’s GP will no doubt have referred them to a specialist after seeing the x-ray report, and making a diagnosis of avascular necrosis.

The specialist will probably want to see your child at least once or twice to make sure there are going to be no real problems.

Medication can be helpful. Simple analgesia, such as paracetamol, will help the child feel more comfortable. Anti-inflammatory medication can help reduce swelling and discomfort.

If the child is finding that the range of movement in their joints is affected, the specialist may suggest physiotherapy and might show the child specific exercises to maintain and try to improve the movement in their affected joint.

Very occasionally, an operation can be helpful but this isn’t necessary in the vast majority of cases.

The child may find that their joint is troublesome for 12–18 months. After that it should settle in terms of pain.

The condition may leave their elbow with some minor stiffness but this shouldn’t interfere significantly with the way that it works.