Yoeri Bemelmans

Outpatient unicompartimental knee arthroplasty 85 6 In our series, high pain intensitywas themain factor for an overnight stay in our hospital. Berger et al. [4] found that 3.6% of the TKA patients could not be discharged on the day of surgery due to inadequate pain control. Painmanagement is one of the key factors for acceptable outcomes of multidisciplinary outpatient pathways [4]. This includes a well- established multimodal protocol, consisting peri-operative LIA [3,12] and an optimised pain protocol for pre-, peri- and postoperative analgesia. The optimised pain protocol also intended to prevent side effects of medication, which enables patients to mobilize <4hrs postoperative. Only one patient (RR) could not mobilize due to PONV. As we know, these preventions are crucial for early mobilization [11] and length of hospital stay [25]. Our discharge results could be influenced by the use of tranexamic acid and dexamethasone in the OS pathway, since there is extensive literature on the advantages of using thesemedications during arthroplasty procedures in the prevention of blood loss [34] and PONV [2]. This could be seen as a confounder in our series, although none of the patients in the OS and RR pathway needed blood transfusion or had a prolonged hospital stay due to wound leakage. Even though the amount of patients with PONV was lower in the OS pathway without a significant difference. Another possible reason for prolonged hospital stay is fear to go home, as found by Berger et al. [4]. Therefore, fear to go home must be included as exclusion criteria for the OS pathway, which was seen in one patient in the OS pathway, resulting in prolonged hospital stay with discharge the first day postoperative. Other causes that can delay discharge are administrative failures [3, 30] but were not seen in our series. AE’s and readmission rates were not significantly different between both groups. This was in line with the results published by others (Table. 4). More complications <1 week postoperativewere seen after TKA rather thanUKAduring the outpatient procedure [4]. Previous series published by Berger et al. [5], showed fewer complications for outpatient TKA, in which they used more stringent inclusion criteria. Recently, Lovald et al. [24] concluded that pre-existing co morbidities and particularly heart failure are major risk factors for AE’s after outpatient and short stay TKA. Furthermore, evidence to in- or exclude patients in an outpatient setting is limited. Beside the pre-selected patients in our series, based on general criteria, we suggest that there is a need for proper in- and exclusion criteria for outpatient knee arthroplasty.