LAUSR

Abstract Introduction COVID-19 is associated with an increased risk of venous thromboembolism (VTE). We compared the incidence of VTE on a busy hip fracture unit during 2020 with previous years to identify factors that may have played a role in its development. Methods Data were retrospectively obtained by notes review for patients admitted with neck or shaft of femur fracture. This included baseline characteristics, comorbidities and operative risk factors for VTE. Results 11 of 420 patients (2.6%) were diagnosed with VTE in 2020, compared with 25 of 2,115 patients (1.2%) between January 2015 and December 2019 (RR 2.2 [95% CI 1.1 to 4.5, p < 0.05]). Only one patient in 2020 had confirmed COVID-19. Retrospective data between 2015–2019 were incomplete, and so statistical analysis of demographic and operative risk factors was not conducted. Descriptive statistics show there were comparable proportions of smokers and malignancy in both groups, and the majority of patients in both groups received either mechanical or pharmacological VTE prophylaxis. A higher proportion of patients were independently mobile prior to admission in 2020 (72.7% vs 28%). There was a shorter interval to development of VTE in 2020 (mean 12 days in 2020 vs 25 days in 2015–2019). Conclusion Following hip fracture surgery patients were twice as likely to develop venous thromboembolism in 2020 than in the previous five years. There was also a shorter time to development of VTE. This was despite a higher reported level of premorbid mobility in 2020 in otherwise similar patient groups. We hypothesise that isolation due to the COVID-19 lockdown contributed to this result. This suggests a need for enhanced vigilance and prompt VTE prophylaxis in this vulnerable population in the event of further pandemic waves and lockdowns.