Final answer:
The most important assessment finding to consider in a child with hemophilia A and repeated hemarthrosis is decreased range of motion, as it signifies joint deterioration due to ongoing internal bleeding.
Step-by-step explanation:
In a child with hemophilia A who has suffered repeated episodes of hemarthrosis, the most important assessment finding to consider is a decreased range of motion. Hemophilia is a genetic disorder characterized by inadequate synthesis of clotting factors, particularly factor VIII in hemophilia A, which leads to an increased risk of internal bleeding, especially into muscles and joints. Repeated episodes of bleeding into the joint spaces (hemarthrosis) can cause chronic inflammation and damage to the joint structures, including the synovium and cartilage. Over time, this can result in synovial hypertrophy, cartilage destruction, and fibrosis of the joint, causing enlargement of the joint space and a consequent decrease in range of motion. Therefore, decreasing the range of motion is a critical indicator of hemophilic arthropathy and joint deterioration in hemophilia patients.