Estimating the Nosocomial Transmission Rate of COVID-19 in Orthopaedic Surgery Patients During the Peak of the Pandemic.

Purpose: To estimate the risk of hospital-acquired COVID-19 transmission in a population of orthopaedic trauma patients during the first wave of the pandemic. Patients and Methods: This is a retrospective cohort study of 109 patients who underwent an emergent orthopedic procedure by a single orthopedic traumatologist between March 1, 2020 and May 15, 2020 during the first peak of the pandemic. After applying inclusion and exclusion criteria, a total of 82 patients (67 inpatients and 15 ambulatory) were identified for final analysis. The primary outcome measured was postoperative Coronavirus (COVID-19) status. Secondary outcome measures included length of stay and discharge disposition. Results: The mean age and length of stay in the hospital group was 59.5 years (± 21.7) and 4.3 days (± 4.6), respectively, versus 47.9 years (± 9.8) in the ambulatory group. 7.3% (6/82) of the inpatients subsequently tested or screened positive for COVID-19 at 2 weeks post-operatively, compared to 0/15 ambulatory patients (P=0.58). Of the 6 inpatients who tested positive, 4 (66.7%) were discharged to a rehabilitation center. Diabetes (P=0.05), hypertension (P=0.02), and congestive heart failure (P=0.005) were associated with transmission. Conclusion: In this analysis, there was a nosocomial transmission rate of 7% compared to zero in the ambulatory surgery center, however this was not found to be statistically significant. This data supports the use of precautions such as frequent screening, hand washing, and masks to reduce transmission when COVID-19 rates are high. There is a lower risk of nosocomial COVID-19 transmission for patients treated as an outpatient and elective surgical procedures may be safer in this setting.