Mortality in COVID-19 patients after proximal femur fracture surgery: a systematic review and meta-analysis

Background: COVID-19 infection first emerged in December 2019 in China and has since rapidly spread to become a worldwide pandemic. Orthopaedic surgery suffered a significant decline in the volume of surgical cases, while the orthopaedic trauma services maintained or increased the activity. Emergency operations for proximal femur fractures (PFF) in the elderly population assumed levels comparable to before the pandemic, with the 1-year mortality rate ranging from 14% to 36%. Aims: To determine whether patients with PFF affected by COVID-19 have a higher risk of postoperative mortality through a systematic review and meta-analysis. Methods: PubMed, Web of Science, Scopus and BMC were searched from January 2020 to January 2021 to identify original studies reporting the mortality in COVID-19 patients after PFF surgery. Study and participants' characteristics, mortality rate and odds ratio (OR) were extracted. Risk of bias assessment was carried, and visual inspection of the funnel plot was used to assess publication bias. A random-effects model for meta-analysis was adopted. Results: Among 656 articles that came from the search query and hand-search, 10 articles were eligible after applying inclusion and exclusion criteria. Overall, the sum of the study participants was 1882, with 351 COVID-19 positive patients (18.7%) and a total number of 117 deaths, with an overall mortality rate of 33.3%. The mortality rate of COVID-19 positive patients varied from 14.8% to 60% and was higher than of those without COVID-19, with OR ranging from 2.424 to 72.00. The inverse variance method showed an OR = 3.652. All studies showed a statistically significant p-value. Conclusions: The postoperative mortality in hip fracture patients with concomitant COVID-19 was 3.65 times higher than the mortality in non-COVID patients. The currently available literature demonstrates that COVID-19 infection represents a substantial risk factor for postoperative mortality in the already susceptible hip fracture population.