Optimal imaging strategy for community-acquired Staphylococcus aureus musculoskeletal infections in children.

BACKGROUND: Invasive musculoskeletal infections from community-acquired methicillin-resistant and methicillin-susceptible Staphylococcus aureus (CA-SA) are increasingly encountered in children. Imaging is frequently requested in these children for diagnosis and planning of therapeutic interventions.

OBJECTIVE: To appraise the diagnostic efficacy of imaging practices performed for CA-SA osteomyelitis and its complications.

MATERIALS AND METHODS: A retrospective review was conducted of the clinical charts and imaging studies of CA-SA osteomyelitis cases since 2001 at a large children's hospital.

RESULTS: Of 199 children diagnosed with CA-SA osteomyelitis, 160 underwent MRI examination and 35 underwent bone scintigraphy. The sensitivity of MRI and bone scintigraphy for CA-SA osteomyelitis was 98% and 53%, respectively. In all discordant cases, MRI was correct compared to bone scintigraphy. Extraosseous complications of CA-SA osteomyelitis detected only by MRI included subperiosteal abscesses (n = 77), pyomyositis (n = 43), septic arthritis (n = 31), and deep venous thrombosis (n = 12).

CONCLUSION: MRI is the preferred imaging modality for the investigation of pediatric CA-SA musculoskeletal infection because it offers superior sensitivity for osteomyelitis compared to bone scintigraphy and detects extraosseous complications that occur in a substantial proportion of patients.