The successful and safe conversion of joint arthroplasty to same-day surgery: A necessity after the COVID-19 pandemic.

Introduction: A key strategy to address system pressures on hip and knee arthroplasty through the COVID-19 pandemic has been to shift procedures to the outpatient setting.

Methods: This was a retrospective cohort and case-control study. Using the Discharge Abstract Database and the National Ambulatory Care Reporting System databases, we estimated the use of outpatient hip and knee arthroplasty in Ontario, Canada. After propensity-score matching, we estimated rates of 90-day readmission, 90-day emergency department (ED) visit, 1-year mortality, and 1-year infection or revision.

Results: 204,066 elective hip and 341,678 elective knee arthroplasties were performed from 2010-2022. Annual volumes of hip and knee arthroplasties increased steadily until 2020. Following the start of the COVID-19 pandemic (March 1, 2020) through December 31, 2022 there were 7,561 (95% CI 5,435 to 9,688) fewer hip and 20,777 (95% CI 17,382 to 24,172) fewer knee replacements performed than expected. Outpatient arthroplasties increased as a share of all surgeries from 1% pre-pandemic to 39% (hip) and 36% (knee) by 2022. Among inpatient arthroplasties, the tendency to discharge to home did not change since the start of the pandemic. During the COVID-19 era, patients receiving arthroplasty in the outpatient setting had a similar or lower risk of readmission than matched patients receiving inpatient arthroplasty [hip: RR 0.65 (0.56-0.76); knee: RR 0.86 (0.76-0.97)]; ED visits [hip: RR 0.78 (0.73-0.83); knee: RR 0.92 (0.88-0.96)]; and mortality, infection, or revision [hip: RR 0.65 (0.45-0.93); knee: 0.90 (0.64-1.26)].

Conclusion: Following the start of the COVID-19 pandemic in Ontario, the volume of outpatient hip and knee arthroplasties performed increased despite a reduction in overall arthroplasty volumes. This shift in surgical volumes from the inpatient to outpatient setting coincided with pressures on hospitals to retain inpatient bed capacity. Patients receiving arthroplasty in the outpatient setting had relatively similar outcomes to those receiving inpatient surgery after matching on known sociodemographic and clinical characteristics.