F8 and hemarthrosis: Hemophilia is a X-linked congenital coagulopathy characterized by a deficit of clotting factors: hemophilia A (clotting factor VIII [FVIII]) or hemophilia B (clotting factor IX [FIX]).[1] The main clinical symptoms are joint bleeding (hemarthrosis).[2] The recurrence of bleeding episodes leads to the development of synovial hypertrophy and bone and cartilage destruction.[3] Consequences for the joint as a result of a succession of repeated hemarthrosis events in a single joint include hemophilic arthropathy.[4]