Incidence of shoulder prosthetic joint infection throughout the COVID-19 pandemic

Background

1-2% of patients who undergo anatomic and reverse total shoulder arthroplasty are diagnosed with a prosthetic joint infection (PJI), which requires revision surgery, prolonged recovery and rehabilitation, and antibiotic treatment. During the COVID-19 pandemic, anecdotal evidence suggested an increased rate of PJI among all patient populations. However, there have been no studies characterizing PJI incidence following shoulder arthroplasty during the COVID-19 pandemic. In the present study, we sought to evaluate the incidence of shoulder PJI during the COVID-19 pandemic.

Methods

Patients undergoing revision shoulder arthroplasty for PJI at an academic medical center between 2017 and 2021 were identified: patients before COVID-19 (2017-2019) and patients during COVID-19 (2020-2021). Patient demographics, laboratory data, history of COVID-19 infection and vaccination, antibiotic treatment, and final surgical treatment were collected. Patient-reported outcome measures (American Shoulder and Elbow Surgeons Shoulder Score, Single Assessment Numeric Evaluation, surgical Apgar score, Patient-Reported Outcome Measurement Information System (physical function, pain intensity, upper extremity, global 10), and Veterans RAND 12-item Health Survey or Medical Outcomes Study short-form health survey version 2) were collected. PJI incidence was calculated from a retrospective chart review, which identified patients with PJI as defined by the International Consensus Meeting on musculoskeletal infection in 2018 and who underwent revision surgery and antibiotic treatment. Incidence rate analysis and independent t-tests were conducted to compare the mean baseline patient-reported outcome measures. Descriptive analysis of the collected data included means and standard deviations for continuous variables and frequencies and percentages for discrete variables. Statistical significance was set at a P value < .05.

Results

46 patients were identified with 20 patients undergoing a revision surgery for a PJI during the pre-COVID-19 time interval and 26 during the COVID-19 time interval. 20% underwent single-stage revision (4 pre-COVID-19 and 5 during COVID-19), 50% underwent two-stage revision (10 pre-COVID-19 and 13 during COVID-19), and 30% underwent a debridement, antibiotics, and implant retention procedure (6 pre-COVID-19 and 8 during COVID-19). There was a significant increase in shoulder PJI infections between the pre-COVID-19 time interval and during COVID-19, with PJI incidence rates of 1.1% and 2.1%, respectively (P = .028). There was no significant difference in any outcome scores, microbes on aspiration, inflammatory markers, or duration of treatment between the two time intervals.

Conclusion

While this study does not show clear evidence to an underlying mechanism explaining the increased PJI incidence observed during the COVID-19 pandemic, this study does show a significant increase in the rate of shoulder PJI status post shoulder arthroplasty during COVID-19. Further investigation into how the vaccine and COVID-19 infection may affect the body’s immune system may provide insight into this increase.