Which of the following is a marker for osteoarthritis?

Heberden's nodes are specifically indicative of osteoarthritis, making them a key marker of this condition. These nodes are bony growths that occur on the distal interphalangeal (DIP) joints of the fingers and are considered characteristic findings associated with osteoarthritis. They result from the degeneration of cartilage and the formation of bony hypertrophy in response to the wear and tear of the joints.

While morning stiffness, joint swelling, and severe joint pain can occur in various types of arthritis, including osteoarthritis, they are not exclusive to it. Morning stiffness, for instance, is more prominent in inflammatory conditions, such as rheumatoid arthritis, and typically lasts less than 30 minutes in osteoarthritis. Joint swelling might reflect inflammation and is not a defining feature of osteoarthritis, as swelling tends to be more significant in inflammatory arthritis. Severe joint pain can occur in multiple arthritic conditions and does not specifically indicate osteoarthritis alone. Therefore, Heberden's nodes stand out as a definitive marker specific to osteoarthritis.