Peculiarities of osteo-articular infections in children.

Paediatric osteomyelitis is uncommon in the developed world, haematogenous spread of infection being the most prevalent cause in children. The metaphyses of the long bones are the sites involved in most cases, but in neonates the infection may spread to the contiguous epiphysis and joint. Staphylococcus aureus is the main causal organism in all groups. Plain X-rays take at least 7 days to show the first signs of osteomyelitis. Bone scans show change earlier, with a high sensitivity but a lower specificity. Magnetic resonance imaging and computed tomography are useful, if expensive, imaging techniques but usually require sedation in children. The causal micro-organisms may be identified from blood cultures, fine-needle aspiration or surgical drainage. Antimicrobial therapy should be given for 3-4 weeks, initially via the intravenous route and later switching to oral medication. Surgery is indicated for the drainage of acute abscesses or when there has been no improvement with antibiotics; it is essential in the treatment of chronic osteomyelitis.