Yoeri Bemelmans

General introduction 9 1 General introduction Osteoarthritis (OA) is one of themost common forms of arthritis and chronic disease of the hip and knee joints [1]. It is affectingmillions of people worldwide and is projected to increase evenmore due to ageing of the global population.When conservative treatment fails, end-stage OA of the hip and knee joint is commonly treated with arthroplasty surgery. These surgeries have proven to achieve long-lasting improvement of disability and pain symptoms with restoring patients’ quality of life [2]. Over the past decades, these arthroplasty procedures are increasingly performed and are expected to increase even more in the upcoming years. Estimations in the United States projected a raise of primary hip arthroplasty up to 174%, and a growth of primary knee arthroplasty with 673% by 2030 [3]. Making these operations one of the most performed and successful surgeries worldwide within orthopaedic care. Clinical pathways Over the past decade, hip and knee arthroplasty surgeries evolved rapidly. Minimal invasive techniques were developed, for example patient-specific instruments were introduced, and thereby outcomes after surgery improved [4]. Besides these technical solutions, the optimisation of the ‘patient journey’ towards this result is becomingmore important. Traditionally, patients undergoing hip and/or knee arthroplasty are treated in so-called joint arthroplasty pathways. These pathways are defined as a combination of evidence-based clinical features included in the pre-, peri-, and postoperative protocols, with its aim to streamline the arthroplasty procedure from admission to discharge. The main goals are to reduce mortality, morbidity and to improve (medical and functional) outcome during and after surgery. Ideally, the usage of these pathways results in a decreased length of hospital stay (LOS) and improved patient satisfaction regarding the complete surgical process [5]. From a historical point of view, patients were in the hospital for several weeks after arthroplasty surgerywithobligatedbed rest for thefirst daysup to severalweeks. Patients were then mobilised with restricted weight-bearing during their hospital stay. This resulted in a high level of comorbidities and (serious) adverse events ((S)AEs) regarding arthroplasty surgery (e.g. risk of thrombosis, high percentage of perioperative blood transfusions and extensive use of (opioid) pain medication resulting in postoperative nausea and vomiting (PONV)). In the late 90’s, arthroplasty pathways were optimised. Several introductions were made to prevent for blood transfusions (e.g. autologous transfusion of drain content, preoperative erythropoietin usage), reduce pain experience (e.g. patient controlled