Heberden's nodes are most commonly located at which joints?

• A. PIP joints
• B. DIP joints
• C. MCP joints
• D. CMC joint of the thumb

Answer: (B)

Heberden's nodes are bony enlargements at the distal interphalangeal joints caused by osteophyte formation in hand osteoarthritis. They occur most commonly at the DIP joints—the joints closest to the fingertip. By contrast, Bouchard nodes appear at the proximal interphalangeal joints, and rheumatoid arthritis typically involves the MCP and PIP joints rather than the DIP. So the DIP location of these nodules is the hallmark feature.