What is the most common cause of hemophilic arthropathy?

The most common cause of hemophilic arthropathy is related to impaired clotting factors leading to joint bleeding. In individuals with hemophilia, the deficiency of specific clotting factors (such as factor VIII in hemophilia A or factor IX in hemophilia B) results in a propensity for bleeding, including into the joints. This repeated bleeding episodes into the joint spaces lead to pain, swelling, and inflammation, often becoming chronic.

As bleeding occurs, the resultant hematomas can increase intra-articular pressure and lead to synovial inflammation known as synovitis. Over time, this chronic bleeding and inflammation can contribute to joint damage, including fibrosis and hemophilic arthropathy, which involves pain, reduced range of motion, and degeneration of the joint.

While iron deposition and chronic inflammation from immune response may occur, they are secondary complications rather than primary causes of hemophilic arthropathy. Joint misalignment due to muscle weakness can also play a role in the overall functional impairment of joints, but again it stems from the primary problem of repeated bleeding and subsequent joint damage. Therefore, the initial factor in the development of hemophilic arthropathy is primarily due to the impaired clotting mechanisms that lead to joint bleeding.