Undocumented traditions in perioperative care after total hip and knee arthroplasty are passed on as gold standard. However, evidence-based medicine may interfere with traditions. It is therefore essential to revisit traditions or routines once in a while and re-evaluate current practice according to existing evidence. Fast track surgery is an example of replacing traditions with evidence-based clinical features in order to optimise perioperative outcome. This article reviews some traditions that may influence outcome regarding pain, infection, blood loss, mobilisation, length of stay in hospital, thromboembolic prophylaxis, and costs.