Osteomyelitis (osteo- derived from the Greek word osteon, meaning bone, myelo- meaning marrow, and -itis meaning inflammation) simply means an infection of the bone or bone marrow. It can be usefully subclassified on the basis of the causative organism (pyogenic bacteria or mycobacteria), the route, duration and anatomic location of the infection.
CauseAge group Most common organisms
Newborns (younger than 4 mo) S. aureus, Enterobacter species, and group A and B Streptococcus species
Children (aged 4 mo to 4 y) S. aureus, group A Streptococcus species, Haemophilus influenzae, and Enterobacter species
Children, adolescents (aged 4 y to adult) S. aureus (80%), group A Streptococcus species, H. influenzae, and Enterobacter species
Adult S. aureus and occasionally Enterobacter or Streptococcus species
Sickle Cell Anemia Patients Salmonella species
Diagnosis of osteomyelitis is often based on radiologic results showing a lytic center with a ring of sclerosis. Culture of material taken from a bone biopsy is needed to identify the specific pathogen; alternative sampling methods such as needle puncture or surface swabs are easier to perform, but do not produce reliable results.
Factors that may commonly complicate osteomyelitis are fractures of the bone, amyloidosis, endocarditis, or sepsis.
Osteomyelitis of the tibia of a young child showing numerous abscesses in the bone as radiolucency.