The third PBM pillar, use of low Hb cut-off levels triggering transfusion, means that a certain degree of postoperative anaemia is taken into account. However, it remains unclear whether a lowered transfusion threshold allows optimal functional recovery and quality of life. Since patients undergoing total knee arthroplasty (TKA) are often elderly and have several comorbidities, prolonged exposure to low Hb levels is not a good option for this population. Furthermore, TKA patients should be mobilised as soon as possible after surgery which increases the metabolic demand.