title: Outpatient unicompartmental knee arthroplasty: who is afraid of outpatient surgery?
abstract: OBJECTIVE
  In recent years, duration of hospitalisation after knee arthroplasty has decreased and fast track and outpatient surgery protocols have been developed. Studies have shown that outpatient surgery is feasible, safe, and cost effective. However, the psychological well-being of patients undergoing outpatient surgery has never been described before. The purpose of this study was to investigate how patients experience outpatient surgery for unicompartmental knee arthroplasty (UKA), examining levels of anxiety and depression, satisfaction, and pain. It was hypothesized that the same-day discharge following UKA would not result in higher levels of anxiety and depression, compared to the standard fast-track surgery.
  
  
  METHODS
  This case-controlled study included 20 patients undergoing UKA in an outpatient surgery setting and 20 patients undergoing the standard fast-track procedure. The Hospital Anxiety and Depression Scale (HADS, 0-42, lower is better) and numeric rating scales (NRS, 0-10) for pain and satisfaction were collected preoperatively, on the day of surgery, on the first, second, and seventh postoperative days and after 6 and 12 weeks. The Oxford Knee Score (OKS), the KOOS, EuroQoL-5D, and Net Promoter Score (NPS) were collected preoperatively and 3 months postoperatively.
  
  
  RESULTS
  90% of patients in the outpatient surgery group were discharged on the day of surgery. At the first postoperative day, the median HADS score was significantly lower in the outpatient surgery group compared to the fast-track group (3 vs. 8, p = 0.02), the median NRS satisfaction score was significantly higher in the outpatient surgery group (8 vs. 5, p = 0.03), and no differences existed between both groups for the NRS pain scores. At 3 month follow-up, no significant differences in improvement scores existed between both groups for the HADS, the NRS scores, and for the OKS, KOOS, EuroQoL-5D, and NPS.
  
  
  CONCLUSIONS
  The results of this study emphasize the feasibility of an outpatient surgery pathway in carefully selected UKA patients. The outpatient surgery pathway is safe, and clinical outcome, including levels of anxiety and depression, satisfaction, and pain, was similar in outpatient surgery patients compared to the standard fast-track patients.
  
  
  METHODS
  Case-control study, Level III.
authors.affiliation: Department of Orthopaedic Surgery, Foundation FORCE (Foundation for Orthopaedic Research Care Education), Amphia Hospital, Postbus 90158, 4800 RK, Breda, The Netherlands. shoorntje@amphia.nl.
authors.forename: Alexander
authors.identifier: http://orcid.org/0000-0002-4268-9526
authors.initials: A
authors.lastname: Hoorntje
authors.affiliation: Department of Orthopaedic Surgery, Foundation FORCE (Foundation for Orthopaedic Research Care Education), Amphia Hospital, Postbus 90158, 4800 RK, Breda, The Netherlands.
authors.forename: Koen L M
authors.initials: KLM
authors.lastname: Koenraadt
authors.affiliation: Department of Orthopaedic Surgery, Foundation FORCE (Foundation for Orthopaedic Research Care Education), Amphia Hospital, Postbus 90158, 4800 RK, Breda, The Netherlands.
authors.forename: Margreet G
authors.initials: MG
authors.lastname: Boevé
authors.affiliation: Department of Orthopaedic Surgery, Foundation FORCE (Foundation for Orthopaedic Research Care Education), Amphia Hospital, Postbus 90158, 4800 RK, Breda, The Netherlands.
authors.forename: Rutger C I
authors.initials: RCI
authors.lastname: van Geenen
mesh_terms: D000556:Ambulatory Surgical Procedures / Q000523:psychology*; D001007:Anxiety / Q000175:diagnosis; D018771:Arthralgia / Q000175:diagnosis; D019645:Arthroplasty, Replacement, Knee / Q000379:methods* / Q000523:psychology*; D016022:Case-Control Studies; D003863:Depression / Q000175:diagnosis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D011184:Postoperative Period; D016896:Treatment Outcome
keywords: Day care; Enhanced recovery; Fast track; Outpatient surgery; PROMs; Unicompartmental knee arthroplasty