BackgroundThe COVID-19 pandemic has had a significant impact on orthopaedic trauma worldwide, but the extent of this impact regarding the low-risk period is still unclear. This study aims to evaluate the epidemiology of open limbs fractures during the different risk periods and the effect of routine prevention and control measures.MethodsA retrospective multi-centre cohort study was conducted in three different level trauma centres. Three 60-day periods were analyzed: the high-risk period - 2020/1/24-2020/3/24, the low-risk period - 2021/1/24-2021/3/25, and the no-risk period as a control group for comparison - 2019/1/24-2019/3/25. Demographic data, medical history, and surgery and antibiotic therapy data at presentation were collected and evaluated.ResultsA total of 123 patients met the inclusion criteria. We observed a significant "J" shaped change in the total number of patients, with fewer patients in 2020 (n=34, -17%) and more in 2021 (n=48, +17%) compared to 2019 (n=41). However, fewer patients visited the level I centre in the low-risk period (82.9% 2019 vs. 70.6% 2020 vs. 56.3% 2021, P=0.024). Meanwhile, longer antibiotics therapy period (>48 hours) were more prevalent in low-risk period (39% 2019 vs. 58.8% 2020 vs. 68.8% 2021, P=0.018). Regarding definitive closure type, increase in direct closure was observed in high-risk period (51% 2019 vs. 78.9% 2020 vs. 63.5% 2021, P=0.024). ConclusionDuring the high-risk period, the total number of patients was expected to decline, whereas in the low-risk period, the number may increase. They preferred the lower level II and III centre for patients during the pandemic rather than the higher level I centre. For surgeons, they were prone to direct closure and a more extended antibiotic therapy period. Routine prevention and control measures seem not adversely affect the treatment outcomes and process of open fractures.Trial registrationChiCTR, ChiCTR 2100046151. Registered 5 May 2021, http://www.chictr.org.cn/edit.aspx?pid=123490&htm=4.