Tumor biology and incidence

  • Most common in children, with two age peaks: children less than age 2 and children between ages 8 and 10 
  • Blood flow through metaphyseal bone slows in growing bones of children, allowing for more turbulent flow and decreased phagocytosis; predispose to infection
  • Staphylococcus aureus most common infecting organism

Presentation and physical findings

  • In early stages, may not present with systemic signs
  • In chronic form, patients may present with history of pain of several months’ duration.
  • Blood work
    • Normal to elevated white blood cell count
    • Elevated erythrocyte sedimentation rate (ESR); usually takes 3-5 days to reach its peak
    • Elevated C-reactive protein; reaches peak by day 2 postinfection; more accurate than ESR for monitoring progress of treatment.

Radiographic appearance

Within 24 hours of infection
  • Evidence of osteomyelitis
  • Soft tissue swelling, loss of definition between fascial planes
Within 7-10 days of infection
  • Destructive lytic lesion may be present
  • Lesion positive on bone scan
Within 2-6 weeks of infection
  • Progressive bony destruction of cortical and medullary bone
  • Endosteal sclerosis and periosteal reaction are usually present.
Within 6-8 weeks of infection
  • Sequestra, indicating areas of necrotic bone
  • May be surrounded by a dense involucrum (periosteal new bone formation)

Nuclear medicine

  • Technetium 99m diphosphinate bone scan indicated in most cases
    • False negatives increased if performed in first 24 hours after infection
    • False positves seen with trauma and tumor
  • Sequential technetium-gallium excellent at finding vertebral osteomyelitis
  • Indium-labelled leukocyte scan more accurate for detecting subclinical osteomyelitis


Superior to indium-labelled leukocyte scan in defining extent of infection

Differential diagnosis

  • In acute stage, eosinophilic granuloma and Ewing sarcoma
  • Can simulate many conditions


  • Reactive inflammatory cell infiltrate (lymphocytes and plasma cells)
  • Neutrophils generally not present
  • Mixed cellular infiltrate usually indicates a benign diagnosis
  • Necrotic bone and marrow fibrosis also present

Diagnosis and treatment

  • Individualize to specific case
  • All patients will require antibiotics, with or without surgical debridement

Associated condition: Brodie’s abscess

  • Form of chronic osteomyelitis usually seen in lower extremities of young adults
  • Often insidious bone infection; usually localized to metaphysis of tibia or femur
  • Usually has elongated shape and well-demarcated margin; surrounded by reactive sclerotic bone
  • May see radiolucent tract extending away from lesion into growth plate
  • Sequestra usually absent