Pelvic fractures: epidemiology and predictors of associated abdominal injuries and outcomes.

BACKGROUND Pelvic fractures are often associated with major intraabdominal injuries or severe bleeding from the fracture site. OBJECTIVE To study the epidemiology of pelvic fractures and identify important risk factors for associated abdominal injuries, bleeding, need for angiographic embolization, and death. METHODS Trauma registry study on pelvic fractures from blunt trauma. Stepwise logistic regression was used to identify risk factors of severe pelvic fractures, associated abdominal injuries, need for major blood transfusion, therapeutic embolization, and death from pelvic fracture. Adjusted relative risks and 95% confidence intervals were derived. RESULTS There were 16,630 trauma registry patients with blunt trauma, of whom 1,545 (9.3%) had a pelvic fracture. The incidence of abdominal injuries was 16.5%, and the most common injured organs were the liver (6.1%) and the bladder and urethra (5.8%). In severe pelvic fractures (Abbreviated Injury Scale [AIS] > or =4), the incidence of associated intraabdominal injuries was 30.7%, and the most commonly injured organs were the bladder and urethra (14.6%). Among the risk factors studied, motor vehicle crash is the only notable risk factor negatively associated with severe pelvic fracture. Major risk factors for associated liver injury were motor vehicle crash and pelvis AIS > or = 4. Risk factors of major blood loss were age > 16 years, pelvic AIS > or =4, angiographic embolization, and Injury Severity Score (ISS) > 25. Age> 55 years was the only predictor for associated aortic injury. Factors associated with therapeutic angiographic embolization were pelvic AIS > or =4 and ISS > 25. The overall mortality was 13.5%, but only 0.8% died as a direct result of pelvic fracture. The only pronounced risk factor associated with mortality was ISS>25. CONCLUSIONS Some epidemiological variables are important risk factors of severity of pelvic fractures, presence of associated abdominal injuries, blood loss, and need of angiography. These risk factors can help in selecting the most appropriate diagnostic and therapeutic interventions.