What are the next steps for a patient with suspected pubic osteomyelitis on Computed Tomography (CT) scan without drainage, and should Infectious Disease (ID) specialists be consulted at admission?

Management of Suspected Pubic Osteomyelitis on CT Scan

Infectious Disease consultation should be obtained at admission for patients with suspected pubic osteomyelitis on CT scan, even without drainage, to guide diagnostic workup and optimize antimicrobial therapy. 1

Diagnostic Confirmation

After CT findings suggesting pubic osteomyelitis:

1. MRI evaluation is the next critical step:

   • MRI without and with IV contrast is the preferred imaging modality (rated 9/9 for appropriateness) 2
   • MRI provides superior soft tissue contrast and can delineate the extent of infection 2
   • MRI has >90% sensitivity and >90% specificity for osteomyelitis 1

2. Laboratory studies:

   • Inflammatory markers: CRP, ESR (>27 mm/h suggests infection) 1
   • Blood cultures to identify potential hematogenous spread 1
   • Consider additional cultures if specific pathogens are suspected

3. Bone sampling:

   • Bone biopsy with culture is crucial for definitive diagnosis 1, 3
   • Note: Prior antibiotic use may lead to false-negative cultures 1

Treatment Planning

The ID specialist should help coordinate:

1. Antimicrobial therapy:

   • Initial empiric therapy targeting common pathogens (particularly Staphylococcus aureus) 4, 5
   • Therapy should be adjusted based on culture results 1
   • Extended antibiotic course typically required (several weeks) 1, 6

2. Surgical evaluation:

   • Assess need for debridement, especially in chronic cases 1
   • Evaluate for sequestration of infectious foci 5
   • Consider need for hardware removal if present 1

Special Considerations for Pubic Osteomyelitis

• Pubic osteomyelitis accounts for only 2% of hematogenous osteomyelitis cases, making it a rare diagnosis 7
• In athletes, consider prior trauma or injury as predisposing factors 4
• Differentiate from non-infectious osteitis pubis, which presents with similar symptoms but requires different management 7

Pitfalls to Avoid

• Delayed ID consultation: Early specialist involvement improves outcomes by ensuring appropriate diagnostic workup and targeted therapy
• Relying solely on CT findings: CT is less sensitive than MRI for early osteomyelitis 2
• Inadequate bone sampling: Proper sampling is essential for accurate microbiological diagnosis 1
• Premature antibiotic discontinuation: Inadequate duration of therapy increases risk of chronic infection 6

Follow-up Recommendations

• Serial inflammatory markers to monitor treatment response
• Follow-up imaging to assess resolution of infection
• Long-term ID specialist follow-up to ensure complete eradication of infection

The American College of Radiology guidelines strongly support early specialist consultation for complex bone and joint infections to improve patient outcomes and reduce morbidity 2.