Successful same-day discharge in 88% of patients after unicompartmental knee arthroplasty: a systematic review and meta-analysis

PURPOSE: The purpose of this study was to evaluate the effectiveness of day-case unicompartmental knee arthroplasty (UKA) by assessment of successful same-day discharge (SDD), readmission, complication and reoperation rates in the recent literature. METHODS: For this systematic review and meta-analysis, PubMed, Embase and Cochrane Library were comprehensively searched to identify all eligible studies reporting outcomes of day-case UKA. Studies with intended same-day home discharge after UKA were included. A meta-analysis of proportions, using a random-effects model, was performed to estimate overall rates of successful SDD and adverse events. Subgroup analyses were performed for studies including selected patients (i.e., patients had to meet certain patient-specific criteria to be eligible for day-case UKA) and unselected patients (i.e., no additional criteria for day-case UKA), as well as for clinical and registry-based studies. Additional outcomes included reasons for the failure of SDD and patient satisfaction. RESULTS: A total of 29 studies and 9694 patients were included with a mean age of 66 ± 9 years and mean follow-up of 59 days (mean range 30–270 days). Based on 24 studies (2733 patients), the overall successful SDD rate was 88% (95% confidence interval [CI] 80–92). These rates were 91% (95% CI 84–95) across studies with selected patients and 76% (95% CI 55–89) across studies with unselected patients. Overall readmission, complication and reoperation rates were 3% (95% CI 1.9–4.4), 4% (95% CI 2.8–5.2) and 1% (95% CI 0.8–1.3), respectively. Inability to mobilize, nausea and uncontrolled pain were frequently reported reasons for failed SDD. The overall patient satisfaction rate was 94%. CONCLUSION: This systematic review with meta-analysis found an overall successful SDD rate of 88% after UKA in a heterogeneous cohort of selected and unselected patients. Readmission, complication and reoperation rates suggest UKA can be performed safely and effectively as a same-day discharge procedure. LEVEL OF EVIDENCE: Level IV, systematic review of level III and IV studies. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00167-022-07094-0.