Increased 90-Day Mortality and Morbidity Among Patients Recovering From Elective Primary Arthroplasty During the COVID-19 Pandemic in New York City.

All elective procedures were stopped in March 2020 because of the coronavirus disease 2019 (COVID-19) pandemic. We report the 90-day mortality and complications of patients who underwent primary arthroplasty before the stopping of elective procedures at a single academic medical center. A retrospective cohort study was conducted including patients who underwent elective primary arthroplasty between December 2019 and mid-March 2020. Their 90-day postoperative mortality and medical complications were statistically compared with those of a historical cohort from the same operative period in 2019. The 2020 and 2019 cohorts included 372 and 410 patients, respectively. Except for the prevalence of diabetes, there was no significant difference between the two cohorts regarding baseline characteristics or preoperative health. The 2020 cohort had statistically significant higher rates of pneumonia (2.7% vs 0.7%; P=.03), readmission (9.1% vs 5.4%; P=.04), pulmonary embolism (1.6% vs 0.2%; P=.04), and 90-day mortality (1.1% vs 0%; P=.04). The 2020 cohort also had a trend for increased rates of deep venous thrombosis (1.1% vs 0.7%; P=.7) and cardiac complications (1.9% vs 0.5%; P=.07) and no change in emergency department visits (14.0% vs 11.7%; P=.3). There were 7 confirmed cases of COVID-19 in the 2020 cohort and 1 death. This study demonstrates that patients who underwent primary arthroplasty procedures at our institution close to the time of the first wave of the COVID-19 pandemic experienced a statistically significant increase in mortality, pneumonia, pulmonary embolism, and readmission compared with a historical cohort. As elective procedures have resumed during the ongoing pandemic, providers and patients should be aware of these increased risks. [Orthopedics. 2024;47(3):135-140.].