Abstract
Introduction
Neck of femur (NoF) fractures have an inherent 6.5% 30-day mortality as per National hip fracture database(2019). Several studies have demonstrated a higher mortality rate in covid positive NoFs but have been unable to demonstrate whether there are risk factors that contribute to the risk of mortality in this patient group or whether COVID is solely responsible for the higher mortality.
Aims
To assess risk factors that are concurrently present in a fracture NoF cohort that may contribute to higher mortality in COVID positive patients.
Methods
A cross sectional, retrospective study was performed for a period of 1 year starting from 1st March 2020. All surgically treated neck of femur fracture patients having an isolated intra/extracapsular fracture were included in the study. Data fields recorded- patient demographics, date and time of admission, ward discharge, surgery, mode of surgery (fixation/arthroplasty), prehospital AMTS score, residential status and mobility, ASA grade as per anaesthetist's records, date of death (if deceased), cause of death (as per death certificate/ postmortem / coroner's report). Analysis of mortality was carried out by creating a matched comparison group for each risk factor as well as some combinations.
Results
344 patients were surgically treated for a neck of femur fracture in our DGH during the period of 1st March 2020 to 28th February 2021. 46 patients did not receive a COVID swab (reasons unknown) and were excluded from the study. 35 patients had a COVID-19 RT PCR positive test during their hospital stay and 264 patients remained negative. There were 12 deaths in COVID positive patients (34%) and 53 deaths in COVID negative patients (20%) within the time frame of the study. For each risk factor matched group COVID was seen to confer higher mortality in general. There was no mortality in ASA 1 or 2 patients. Mortality rates in matched groups for age and ASA revealed 23.8% mortality in COVID positive as opposed to 17.3% in COVID negative for ASA 3 and 33.3% mortality in COVID positive vs. 28% in ASA 4. 11 out of the 12 COVID positive patients who died had an AMTS score >6. No correlation was seen between COVID positive deaths and preinjury residential status, type of fracture or surgery offered, or preinjury mobility. The average length of hospital stay was much higher for COVID positive patients (19.5days) as compared to 9.5 days for COVID negative patients.
Conclusion
Matched group analysis show that there is a 37.5% increase in COVID positive neck of femur fracture mortality in ASA 3 patients, the same number falls to 17.8% for ASA 4 patients. These figures are much lower compared to other studies in the UK. There is a need to understand the real cause of death in this subset and to improve death certification so that we can differentiate between patients whose mortality is ‘due to’ or ‘With’ COVID.
