Introduction: Outpatient total hip arthroplasty (THA) is increasingly popular. This meta-analysis investigated the potential advantages of outpatient regimes for THA. Methods: This study followed the PRISMA guidelines. PubMed, Web of Science, Google Scholar, Embase, and Scopus databases were accessed in June 2021. All clinical studies investigating outpatient THA were considered. The outcomes of interest were pain, infection, mortality, revision, dislocation, readmission rates, and deep vein thrombosis (DVT). Results: Data from 102,839 patients were included. A total of 52% (153,168 of 102,839 patients) were women. The mean age of patients was 62.6 ± 4.6 years, the mean BMI was 29.1 ± 1.8 kg/m². Good comparability was found in age, BMI, and gender (p > 0.1). No difference was found in pain (p = 0.4), infections (p = 0.9), mortality (p = 0.9), rate of revision (p = 0.1), dislocation (p = 0.9), and readmission (p = 0.8). The outpatient group demonstrated a greater rate of DVT (OR 3.57; 95% CI 2.47 to 5.18; p < 0.0001). Conclusions: In selected patients, outpatient THA can be performed safely with optimal outcomes comparable with inpatient THA. Clear and comprehensive pre-operative planning should involve a multi-disciplinary group composed of orthopaedic surgeons, anaesthesia and rehabilitation specialists, and physiotherapists. Each centre performing outpatient THA should implement continuous homecoming welfare activity, to supervise physiotherapy and monitor anticoagulant therapy.

Introduction: Outpatient total knee arthroplasty (TKA) is attracting growing interest. This meta-analysis compared patient reported outcome measures (PROMs), infection, readmission, revision, deep vein thrombosis (DVT), and mortality rates of outpatient versus inpatient TKA. Methods: This meta-analysis was conducted according to the 2020 PRISMA statement. In August 2021, the following databases were accessed: Pubmed, Web of Science, Google Scholar, Embase. All the clinical trials comparing outpatient versus inpatient (>2 days) TKA were considered. Studies which reported data on revision settings were not considered, nor studies which included patients discharged between one and two days. Results: Data from 159,219 TKAs were retrieved. The mean follow-up was 5.8 ± 7.6 months. The mean age was 63.7 ± 5.0 years and the mean BMI 30.3 ± 1.8 kg/m². Comparability was found in age (p = 0.4), BMI (p = 0.3), and gender (p = 0.4). The outpatient group evidenced a greater Oxford knee score (p = 0.01). The inpatient group demonstrated a greater rate of revision (p = 0.03), mortality (p = 0.003), and DVT (p = 0.005). No difference was found in the rate of readmission (p = 0.3) and infection (p = 0.4). Conclusions: With regards to the endpoints evaluated in this meta-analysis, current evidence does not support outpatient TKA. However, given the limited data available for inclusion and the overall poor quality of the included articles, no reliable conclusion can be inferred. Further high quality clinical trials with clear eligibility criteria are required.