AB0678 RATES OF SURGICAL PROCEDURES OF THE KNEE AND HIP DURING THE “FIRST WAVE” OF COVID 19 IN SWEDEN
Authors: A. Dell’isola, A. Kiadaliri, A. Turkiewicz, V. Hughes, K. Magnusson, J. Runhaar, S. M. A. Bierma-Zeinstra, M. Englund
Journal: Annals of the Rheumatic Diseases (2021)

Background: Many countries imposed lockdowns in March 2020, in anticipation of the “first wave” of COVID-19 and the massive healthcare resources required to meet its acute medical needs. Sweden adopted a different strategy to contain the epidemic, opting for non-binding recommendations. Nonetheless, elective and acute surgical procedures in health care may have been affected. Objectives: To investigate the effect of the “first-wave” of COVID-19 and the government’s response in Sweden on the rates of total joint replacements (TJR), arthroscopies, and fracture surgeries of the knee and hip. Methods: We used register data for the entire population of Skåne, the southernmost region in Sweden with 1.3 million inhabitants (13% of the total Swedish population). We identified all residents aged ≥18 years who between 1 st January 2015 and 31 st November 2020 underwent any of the following surgical procedures of the knee or hip: TJR (TJR due to fracture excluded), arthroscopy, and surgery due to fracture (including TJR). To demarcate pre-event and post-event periods, we established a differentiation point corresponding to mid-March 2020, the timepoint at which the the Swedish Public Health Agency began recommending social distancing, working from home, distance learning for secondary schools and universities,. At the aggregate level, we modelled the number of surgeries per 10,000 adults from January 2015 up to September 2020. We did an interrupted time-series (ITSA) analysis using segmented ordinary least-squares regression to estimate changes in the levels and trends of surgical procedures compared to pre-COVID-19 levels, adjusting for seasonal variations. The month of March was treated as a “phase-in” period to give time for the new recommendations to be implemented. In addition, we estimated the absolute and relative difference (with its 95% confidence interval [CI]) between the predicted and the counterfactual scenario in the monthly number of surgeries from April 2020, where the counterfactual is the rate of surgery that would have been expected if COVID-19 had not happened. To account for the possibility that other co-occurring events may be responsible for the observed changes, we assessed changes in the number of surgeries due to fractures, which are normally treated as emergencies that cannot be cancelled or rescheduled, and thus should be less affected, at least by policies at the hospital level. Results: We identified a total of 20,831 TJRs, 12,156 arthroscopies and 15,041 fracture surgeries of the knee or hip over the study period. The monthly rate of surgeries and ITSAs are presented in Figure 1, with the pre-COVID period starting from February 2019 for readability (Figure 1). The results suggest that in April 2020, there was a decrease of 2.08 (95%CI 1.81; 2.35) TJRs per 10,000 adults which corresponds to a decrease of 74% (95%CI 65%; 85%) when compared to the counterfactual scenario. This was followed by a positive trend signifying a monthly increase of 0.36 (95%CI 0.31; 0.40) TJRs per 10,000 adults. The rate of arthroscopies followed a similar pattern with a decrease of 0.55 (95%CI 0.39; 0.71) arthroscopies per 10,000 adults in April, which corresponds to a 49% decrease (95%CI 28%; 63%) followed by a positive trend signifying a monthly increase of 0.11 (95%CI 0.07; 0.15) arthroscopies per 10,000 adults. The rate of surgery due to knee or hip fractures showed no decrease in April and was followed by a negative trend signifying a monthly decrease of 0.03 (95%CI 0.002; 0.04) surgeries per 10,000 adults. Conclusion: In Sweden, we observed a marked decrease in the number of typical elective knee and hip surgeries such as TJRs and arthroscopies, following the government’s response to Covid-19. We then observed a slow but steady recovery that brought the rates of procedures towards expected levels by Fall 2020, before the “second wave” hit the country. The number of acute fracture surgeries showed no sharp drop, instead showing a steady and slow decline potentially due to reduction in commuting and in physical activities linked to recommendations of social Disclosure of Interests: None declared