Hemophilia A is a rare inherited bleeding disorder caused by mutations in the factor VIII gene. This clotting factor plays an intrinsic role in the blood coagulation pathway. Patients with hemophilia may develop orthopedic manifestations such as hemarthrosis, but multiple malunion of fractures over the knee is rare and difficult to treat.We report a patient with hemophilia A who developed severe knee osteoarthritis along with fracture malunion and nonunion. Total knee replacement was performed using a custom-made modular hinged knee prosthesis (cemented) equipped with extended distal and proximal stems. At 3 years' follow-up, the patient exhibited excellent clinical function and remained satisfied with the surgical outcome. Surgical intervention was accompanied by rigorous coagulation factor replacement.This case highlights various unique scenarios specific to individuals with hemophilia and fracture deformity.©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.