In an older patient with osteoarthritis and multiple Heberden nodes, which joints are affected?

Heberden Nodes Affect the Distal Interphalangeal (DIP) Joints

Heberden nodes are posterolateral firm/hard swellings located at the distal interphalangeal (DIP) joints of the fingers, not the metacarpal joints. 1

Joint Anatomy Clarification

• DIP joints are the joints closest to the fingertips (the last joint on each finger) 1
• Metacarpophalangeal (MCP) joints are the knuckles at the base of the fingers where they meet the hand 1
• Heberden nodes specifically occur at DIP joints, while Bouchard nodes occur at the proximal interphalangeal (PIP) joints (the middle joints of the fingers) 1, 2

Clinical Significance in Hand Osteoarthritis

The characteristic target joints in hand osteoarthritis include DIP joints, PIP joints, thumb base (carpometacarpal joint), and occasionally the index and middle finger MCP joints. 1

Distribution Pattern

• The DIP joints of the index finger are most frequently affected, followed by the thumb interphalangeal joint 3
• Heberden nodes are more common in the dominant hand and in women 3
• The presence of osteoarthritis at one finger joint strongly associates with involvement of the same joint in the opposite hand 1

Diagnostic Value

• Heberden nodes alone have limited diagnostic value (likelihood ratio 0.50-5.50), but when combined with other features, diagnostic accuracy increases substantially 1
• When a patient over 40 years old has Heberden nodes, family history of nodes, and radiographic joint space narrowing, the probability of hand osteoarthritis increases from 20% to 88% 1, 2
• There is a strong association between Heberden nodes and underlying radiographic osteoarthritis features, particularly joint space narrowing (odds ratio range 2.26-21.23) 3

Common Pitfall to Avoid

Do not confuse Heberden nodes (DIP joints) with involvement of the metacarpophalangeal joints. MCP joint involvement is actually rare in primary hand osteoarthritis and should prompt consideration of alternative diagnoses such as rheumatoid arthritis (which mainly targets MCP joints, PIP joints, and wrists), hemochromatosis, or psoriatic arthritis. 1, 4