Symptomatic venous thromboembolism following a hip fracture: Incidence and risk factors in 5,300 patients

Background and purpose Venous thromboembolism (VTE) remains a substantial cause of morbidity and mortality following hip fracture. Previous work has not identified any risk factors associated with the type of hip fracture. We report the incidence of and risk factors for development of symptomatic VTE in patients following a hip fracture. Patients and methods In this prospective study, we collected information on 5,300 consecutive patients who were admitted to a single unit with a hip fracture—in terms of their pre-admission status, details of any operation performed, and details of complications in the form of symptomatic venous thromboembolism. All patients received thromboprophylaxis with heparin. Results The incidence of symptomatic VTE was 2.2% (95% CI: 1.8–2.6). 85% of these events occurred within 5 weeks of the fracture. The statistically significant risk factors for symptomatic VTE were better preoperative mobility, living in one's own home, high mental test score, high preoperative hemoglobin, inter-trochanteric fractures, and fixation with a dynamic hip screw. In multivariate analysis adjusting for sex and age, type of residence on admission, type of fracture, and hemoglobin values on admission remained independently significant. Interpretation We found that the rate of symptomatic VTE using thromboprophylaxis with heparin was low but that there were a number of groups that were at a significantly higher risk of developing VTE. The patients who are particularly at risk appear to be those with a subtrochanteric or intertrochanteric hip fracture; here, the incidence of symptomatic VTE was twice that of intracapsular hip fractures.