 Patients presenting with preoperative anaemia prior to hip and knee arthroplasty has a high risk of receiving allogeneic blood transfusion and anaemia has been associated with increased postoperative morbidity and mortality. While IV-iron administration may raise Hb prior to surgery, existing guidelines for addressing and treating preoperative anaemia is not widely implemented for patients scheduled for elective total joint arthroplasty TJA in Denmark. In addition, causes of preoperative anaemia and the efficacy of preoperative IV-iron administration has not been sufficiently evaluated in elective TJA. 