American Board of Internal Medicine (ABIM) Certification Practice Exam

How is erosive osteoarthritis diagnosed?

1. Clinical symptoms and physical examination

2. Lab findings of inflammation

3. Radiographic evidence of central erosions

4. Patient history of joint trauma

The correct answer is: Radiographic evidence of central erosions

Erosive osteoarthritis is primarily diagnosed through radiographic evidence of central erosions. In this condition, X-rays typically reveal characteristic changes such as joint deformities, central erosions, and subchondral bone cysts particularly in the interphalangeal joints of the hands. These erosions distinctly differentiate erosive osteoarthritis from other types of osteoarthritis, highlighting the inflammatory nature of the involved joints. While clinical symptoms and physical examinations, such as joint swelling and pain, are important for assessing a patient's overall health and may suggest a diagnosis, they lack the specificity needed to definitively identify erosive osteoarthritis. Laboratory findings may show some level of inflammation but are not the primary means of diagnosis. Additionally, a patient history of joint trauma may be relevant to understanding the overall background of a patient’s condition but does not provide the specific evidence needed to diagnose erosive osteoarthritis. Thus, the reliance on radiographic findings is crucial in confirming the diagnosis.