In a 53-year-old with knee OA and hand OA features with Heberden and Bouchard nodes, what is the most likely diagnosis?

• A. Osteoarthritis
• B. Pseudogout
• C. Reactive arthritis
• D. Rheumatoid arthritis

Answer: (A)

The main idea is that this presentation fits osteoarthritis, a degenerative process that commonly affects both weight-bearing joints and the common hand joints with characteristic bony enlargements. Heberden nodes at the distal interphalangeal joints and Bouchard nodes at the proximal interphalangeal joints are classic signs of hand osteoarthritis, reflecting osteophyte formation and cartilage loss. In a 53-year-old, knee involvement plus these hand changes points toward OA rather than an inflammatory arthritis. OA typically causes chronic pain that worsens with activity and improves with rest, with imaging showing joint-space narrowing, subchondral sclerosis, and osteophytes in the affected joints.

Pseudogout would present as an acute inflammatory arthritis, often with sudden knee swelling and warmth due to calcium pyrophosphate crystals, not the slow, asymmetric degenerative pattern with hand nodes. Reactive arthritis features an asymmetric inflammatory arthritis often after infection and may include extra-articular signs. Rheumatoid arthritis tends to involve small joints of the hands bilaterally with long-standing morning stiffness and possible rheumatoid nodules, rather than the Heberden and Bouchard nodes characteristic of OA.