In a child with hemophilia, which joint is most commonly affected by hemarthrosis?

• A. Wrist
• B. Knee
• C. Shoulder
• D. Elbow

Answer: (B)

This item asks which joint is most commonly involved in joint bleeding (hemarthrosis) in a child with hemophilia. The knee is the most frequent site because it’s the largest synovial, weight‑bearing joint and is exposed to frequent minor traumas from everyday activities. Blood from a factor deficiency can accumulate quickly in the knee’s spacious joint cavity, causing swelling, pain, and limited motion. Recurrent bleeding into the knee can lead to chronic synovitis and joint damage if not promptly treated, making it the typical presentation in pediatric hemophilia.

Elbow and ankle can also bleed, and sometimes wrist or shoulder involvement occurs, but none are as commonly affected as the knee.