Osteomyelitis Dr Trisha Macnair Bacteria can cause infection in bones, most often in the knee.

In this article

What is osteomyelitis? Symptoms

Cause and risk factors Treatment and recovery

Osteomyelitis is an infection of the bone, particularly the long bones in children. It commonly affects the bones on either side of the knee but any bone can be affected.

The child usually has a fever and a painful limb that they don't want touched or moved, because this causes intense pain. The skin over the infected bone may be swollen, hot and red.

The child may vomit, complain of nausea, or feel lethargic and weak.

In chronic osteomyelitis, pus may drain through the skin. Sometimes the infection spreads to involve the nearby joint, causing a septic arthritis.

Osteomyelitis is usually caused by bacteria, most commonly Staphylococcus aureus, but many other bacteria can be to blame, and occasionally fungal infections occur.

Osteomyelitis usually results from the spread of micro-organisms through the blood, but sometimes infection spreads from a nearby wound.

Osteomyelitis is most common in children under 1 year old and children between 3-10 years. It is more frequent in boys than girls and often preceded by trauma.

Some conditions, such as sickle cell anaemia, leave people more vulnerable to it.

A child with suspected osteomyelitis should be investigated in hospital. Blood tests are done to look for the bacteria that is causing it. Sometimes a needle will be put into the bone to look for bacteria, especially if pus is suspected. X-rays can help to see if there is any bone damage. Bone scans and ultrasound scans are also used.

Intensive treatment with a long course (weeks) of antibiotics (usually given into a vein) is necessary to reach and clear the infection deep in the bone.

Surgery may be needed to drain the infection, especially if an abscess forms. The limb may at first be rested using a splint, but later physiotherapy and exercise is important.

Most children recover well, especially if the infection is caught early. However, damage to the growth plate in the bone or to the joint can sometimes cause long-term deformity.

Occasionally, a chronic infection develops and these can be more difficult to treat and carry a greater risk of long-term damage.

This article was last medically reviewed by Dr Orlena Kerek in February 2009