In osteoarthritis, Heberden's nodes are located at which joints?

• A. MCP joints
• B. PIP joints
• C. Wrist joints
• D. DIP joints

Answer: (D)

Heberden's nodes are bony enlargements from osteophyte formation at the distal interphalangeal joints of the fingers in osteoarthritis. The DIP joints are the finger joints closest to the fingertips, where these nodules classically develop. The other listed joints aren’t typical sites for Heberden’s nodes—MCP joints are at the base of the fingers, and the wrist isn’t a finger joint; OA at the proximal interphalangeal joints tends to produce Bouchard nodes instead. So the location is the distal interphalangeal joints.