Analysis on risk factors for deep venous thrombosis of lower extremities after hip fracture

Objective To investigate the risk factors of deep venous thrombosis (DVT) of lower extremities after hip fracture and provide reference for the prevention of DVT. Methods A retrospective case-control study was conducted to analyze the clinical data of 167 patients with hip fracture admitted to Daping Hospital of Army Medical University from January 2016 to December 2016, including 75 males and 92 females, aged 18.7-90.3 years [(70.4±17.7)years]. Using the positive results of ultrasound as the standard for confirming the diagnosis of DVT, 79 patients (47.3%) were assigned to the DVT group, and 88 patients (52.7%) to the non-DVT group. Patients' age, gender, body mass index (BMI), smoking history, D-dimer level, osteoporosis, venous thrombosis risk stratification score (RAPT), coronary heart disease, hypertension, diabetes history, anesthesia method (general anesthesia or nerve blocking), type of surgery (joint replacement or internal fixation), operation time were included in the analysis. The correlation between DVT and the above indices was explored through univariate analysis, followed by logistic regression analysis to determine the risk factors of lower extremities DVT after hip fracture. Results The univariate analysis showed that smoking history, D-dimer level, BMI, RAPT score, hypertension, diabetes, coronary heart disease, anesthesia method and operation time were significantly associated with lower extremities DVT after hip fracture. According to the logistics regression analysis, smoking (OR=9.403, P<0.05). D-dimer (OR=0.999, P<0.01), BMI(OR=0.603, P<0.01), RAPT score (OR=0.499, P<0.05), hypertension (OR=28.965, P<0.01), diabetes(OR=6.948, P<0.05), coronary heart disease (OR=17.185, P<0.01), operation time (OR=36.830, P<0.01) were significantly correlated with newly formed lower extremities DVT after hip fracture. Conclusions Smoking, D-dimer level, obesity (BMI≥25 kg/m2), RAPT score, hypertension, diabetes, coronary heart disease and operation time (≥150 minutes) are independent risk factors for lower extremities DVT after hip fracture. D-dimer level detection shows early diagnostic value for hip fracture with DVT. RAPT score can effectively evaluate DVT in trauma patients, thus guiding and preventing the occurrence of DVT. Key words: Hip fractures; Venous thrombosis; Risk factors