American Board of Internal Medicine (ABIM) Certification Practice Exam

What is essential for diagnosing chronic osteomyelitis?

1. Histopathology and full microbiologic studies

2. X-ray imaging

3. Clinical assessment

4. Bone biopsy

The correct answer is: Histopathology and full microbiologic studies

Diagnosing chronic osteomyelitis primarily relies on a combination of clinical assessment and definitive laboratory investigations to confirm the presence of infection. The essential element for an accurate diagnosis is a bone biopsy, which allows for the direct sampling of bone tissue. This procedure enables histopathologic examination and microbiologic studies to identify causative organisms, assess the extent of the infection, and determine whether any necrotic bone is present. While histopathology and full microbiologic studies help confirm the diagnosis, the bone biopsy itself is critical because it provides a definitive sample from the affected area, thereby leading to a reliable diagnosis. This contrasts with imaging, such as X-rays, which may show changes in the bone structure but cannot definitively diagnose the condition. Therefore, while the choice regarding histopathology and microbiologic studies is accurate, it is the bone biopsy that is absolutely essential for diagnosing chronic osteomyelitis, as it combines the need for direct tissue evaluation and pathogen identification.