Heberden's nodes are enlargements at which joints?

• A. PIP joints
• B. DIP joints
• C. MCP joints
• D. Thumb CMC joint

Answer: (B)

Heberden's nodes are bony enlargements at the distal interphalangeal joints of the fingers. They arise from osteophyte formation associated with osteoarthritis of the hand. This site—DIP joints—is the hallmark location for these nodules, distinguishing them from Bouchard nodes, which occur at the proximal interphalangeal joints (PIP). While osteoarthritis can affect other joints such as the thumb CMC, the specific nodular swellings known as Heberden's nodes occur at the DIP joints, making them the best answer.