Introduction to osteomyelitis

Osteomyelitis is the inflammation of bone tissue that is usually caused by infection. Bone infection can occur from haematogenous spread in the setting of a bloodstream infection, contiguous spread of infection from adjacent tissues, or direct inoculation (eg from trauma or surgery).

In these guidelines, antibiotic choice depends on the:

• patient’s age (child or adult)
• duration of infection (acute or chronic)
• anatomical location of the infection, including long bone, mandible, sacrum, sternum and vertebrae.

Acute osteomyelitis refers clinically to a newly recognised bone infection, and is characterised pathologically by the absence of bone necrosis and sequestra (fragments of necrotic bone). Symptoms present for fewer than 14 days correlate with acute osteomyelitis histopathologically.

Chronic osteomyelitis refers clinically to a longstanding or relapsed bone infection that may involve a sinus or a compromised soft tissue envelope. It is characterised pathologically by low-grade inflammation, and may involve sequestra or involucra (new bone formation adjacent to sequestra). When patients present, they have usually had symptoms for months.