18th January 2024

Osteoarthritis (OA)

Despite being easily distinguishable from RA in medical textbooks, OA can cause a diagnostic conundrum in middle-aged or elderly patients when small joints of the hands are involved.

In OA, DIP joints are involved with Heberden’s nodes in this area (whereas DIP joints are spared in RA). Carpometacarpal joint of the thumb is also involved. There may be joint swelling in OA as well as in RA, but the joint swelling in OA is hard and bony, as opposed to soft, warm, boggy and tender in RA.

• Stiffness is usually absent, but if present, it is worse in the evening after exercise. If present in the morning, it lasts no more than a few minutes.
• X-rays show narrowing of joint space due to cartilage loss and osteophytes due to bone remodelling, but not erosions  (Remember LOSS in OA  (Loss of joint space, Osteophytes, Subchondral sclerosis, Subchondral cysts) vs LESS in RA (Loss of joint space, Erosions, Soft tissue swelling, Soft bones (osteopenia)