Osteomyelitis is an infection in the bone and bone marrow. This typically occurs in the metaphysis of the long bones. The most common bacteria is staphylococcus aureus. Chronic osteomyelitis is a deep seated, slow growing infection with slowly developing symptoms. Acute osteomyelitis presents more quickly with an acutely unwell child.
The infection may be introduced directly into the bone, for example during an open fracture. Alternatively it may have travelled to the bone through the blood, after entering the body through another route, such as the skin or gums.
Osteomyelitis is more common in boys and children under 10 years. There is often a risk factor that predisposes the child to developing osteomyelitis:
- Open bone fracture
- Orthopaedic surgery
- Sickle cell anaemia
Osteomyelitis can present acutely with an unwell child, or more chronically with subtle features. Signs and symptoms are:
- Refusing to use the limb or weight bear
They may be afebrile, or may have a low grade fever. Children with acute osteomyelitis may have a high fever, particularly if it has spread to the joint causing septic arthritis.
Xrays are often the initial investigation, but can be normal in osteomyelitis. MRI is the best imaging investigation for establishing a diagnosis. A bone scan is an alternative.
Blood tests will show raised inflammatory markers (CRP and ESR) and white blood cells in response to the infection.
Blood culture is important in establishing the causative organism. A bone marrow aspiration or bone biopsy with histology and culture may be necessary.
Treatment requires extensive and prolonged antibiotic therapy. They may require surgery for drainage and debridement of the infected bone.
Last updated January 2020