Outpatient total hip or knee arthroplasty in ambulatory surgery center versus arthroplasty ward: a randomized controlled trial

Background and purpose — Discharge on the day of surgery (DOS) in selected patients operated with total hip arthroplasty (THA) or total knee arthroplasty (TKA) has been shown to be feasible, but different factors may determine whether patients are discharged on the DOS or not and setting may be one of them. We investigated the importance of the setting in which the short stay following outpatient THA or TKA takes place: was there a difference between the proportion of patients being discharged on the DOS from an ambulatory surgery center (ASC) compared with patients staying on an arthroplasty ward? Patients and methods — 50 patients (30 TKA, 20 THA) were included in the study and postoperatively randomized to either staying in the ASC or the arthroplasty ward until discharge. All patients were operated under general anesthesia by the same experienced surgeon (HH) and were discharged upon fulfillment of standardized discharge criteria. Results — 24/25 of the patients who stayed in the ASC compared with 20/25 of the patients on the arthroplasty ward were discharged on the DOS following fulfillment of discharge criteria (p = 0.08). All THA patients were discharged on the DOS and significantly more TKA patients were discharged from the ASC (15/16) vs. from the ward (9/14) (p = 0.04). Interpretation — Despite fixed discharge criteria, the logistical setting may play a role for achieving discharge on DOS and the ASC may facilitate achieving discharge criteria earlier especially in TKA.