Transient synovitis (irritable hip)

What is irritable hip?

All the freely movable joints of the body have a lubricating lining called the synovial membrane. Irritable hip occurs when the membrane becomes inflamed for a short period of time (otherwise known as ‘transient synovitis’).

The inflammation causes pain. The synovial membrane produces more than its usual thin film of lubricating fluid when it is inflamed and this can result in more pain in the joint.

Irritable hip occurs in children (usually aged between 3 and 10 years) and is more common in boys than girls.

What causes irritable hip?

Unfortunately no one knows the cause. It may be due to a virus, or perhaps a reaction to an infection somewhere else in the body.

What problems can it cause?

The inflammation in the joint sometimes happens after a flu-like illness. A child will complain of pain in one hip on walking. The pain can be felt in the groin, thigh or even the knee on that side. You may notice that your child is walking unevenly or limping.

How is the diagnosis made?

The diagnosis is usually made from the history and description of the problem and from the examination and observation of your child.

It may be that X-rays and / or blood tests are taken, but this is not always necessary. Your doctor will want to rule out other, more serious problems that can look similar to irritable hip.

One of the most important of these is a bacterial infection in the hip, which needs to be diagnosed and treated relatively quickly to prevent any damage occurring to the hip joint.

How should it be treated?

Children with irritable hip may find walking and standing painful. They should be allowed to rest so that pain is avoided.

It may help to lie on their back and find the most comfortable position for their leg.

An anti-inflammatory medicine, such as ibuprofen may be recommended to ease the swelling of the synovial membrane. Simple pain killers such as paracetamol may also help.

Your child should not take part in sporting activity (apart from gentle swimming) for a couple of weeks after the illness.

When to come back to A&E?

You should return to A&E if:

• Your child is not better after 7 days of rest
• Your child develops a high temperature or is generally not well in himself or herself
• Your child is in more pain or is not able to put weight on their leg to walk

In most cases you will have been given a review appointment (often in the Paediatric A&E) in two or three days’ time.