Epidemiology and risk factors for fat embolism in isolated lower extremity long bone fractures

Purpose: Fat embolism syndrome (FES) is a serious complication after orthopedic trauma. The aim of this study was to identify risk factors for FES in isolated lower extremity long bone fractures. Methods: The National Trauma Data Bank “NTDB” study included patients with isolated femoral and tibial fractures. A total of 344 patients with FES were propensity score matched with 981 patients without FES. Multivariate logistical regression was used to identify independent risk factors for FES. Results: FES was diagnosed in 344 (0.03%) out of the 1,251,143 patients in the study populations. In the two matched groups, the mortality was 7% in the FES group and 1% in the No FES group (p < 0.001). FES was associated with an increased risk of ARDS, VTE, pneumonia, AKI, and stroke. Younger age, femur fractures, obesity, and diabetes mellitus were independent predictors of FES. Early operative fixation (≤ 48 h) was protective against FES. Conclusion: FES increases mortality by seven times. Young age, obesity, and diabetes mellitus are significant independent risk factors for FES. Early fixation is independently associated with a reduced risk of FES. Level of evidence: Level III. Study type: Prognostic study.