Yoeri Bemelmans

Physical activity after outpatient and fast-track knee arthroplasty 141 9 Introduction Enhanced recovery pathways and the further development to outpatient surgery (OS) pathways should focus on reduction of surgical stress, postoperative nausea, vomiting (PONV) and pain [12, 14, 15, 32]. With this optimisation, a reduction in the length of hospital stay (LoS) can be possible [16]. Recent literature supports early discharge on the day of surgery [1, 5, 6, 9, 17, 18]. Together with patient-based selection criteria, a change in mindset and a multidisciplinary approach, OS pathways are as safe and efficient as conventional pathways, in terms of readmissions and complications [18, 19]. Nevertheless, the physical activity of patients in the early postoperative phase is still unclear. A more accurate and objective measure of actual physical activity would therefore be useful for predicting performance in patients with specific activity levels. This includes creating reference data, verifying compliance to rehabilitation protocols, objectify outcome and to better manage patient expectations. Furthermore, it creates the possibility to provide activity-based biofeedback to motivate patients. In addition to patient-reported outcome measures (PROMs), acceleration-based gait analysis has been accepted as an objective measurement of functional and clinical outcome in arthroplasty patients [2]. Results have shown that physical function after total knee arthroplasty (TKA), significantly improved within one year postoperative in terms of gait, sit-to-stand and block step-up transfers. These results were found after TKA in an enhanced recovery pathway (ERP), but data on activity after OS TKA are lacking. This single surgeon, comparative case study was designed to investigate clinical outcomes after TKA following an OS pathway compared to the standard ERP, which brings us to the following research questions; first, is there a difference in physical activity of daily life between ERP and OS as assessed with a non-invasive triaxial accelerometer-based Activity Monitor (AM) and secondly, is there a difference in clinical outcome between ERP and OS patients as assessed with PROMs and knee range of motion (RoM). This is the first study to evaluate the physical activity during the early postoperative phase in patients undergoing TKA following anOS pathway. It was hypothesized that therewould be no difference in physical activity PROMs and RoM between both pathways. Materials andmethods Between April 2014 and December 2015, twenty patients gave consent to participate in this prospective observational comparative case study. This study was performed in compliance with the Helsinki Declaration of 1975, as revised in 2000, and was approved by the Institutional Review Board (IRB: Zuyderland-Zuyd, Heerlen, The Netherlands, IRB Nr. 16N33). Patients with disabling unilateral moderate-severe osteoarthritis, who