Risk factors for deep vein thrombosis in lower extremity after orthopedic surgery

Objective To determine the risk factors contributing to deep vein thrombosis (DVT) in the lower extremity after orthopedic surgery.Methods Five thousand one hundred and thirty-three patients of both sexes,aged 18-89 yr,undergoing orthopedic surgery,were included in the study.Visits to patients were performed 1 day before surgery,and age,gender,body weight,diagnosis of diseases,smoking history,complications,medical history,and results of laboratory tests were recorded.General anesthesia,epidural anesthesia or combined spinal-epidural anesthesia,or field block (brachial plexus block or femoral nerve block) was performed during surgery.Ultrasound was performed on 7th day after surgery for detection of DVT.The patients were divided into DVTfree group and DVT group.The method of anesthesia,type and duration of surgery,postoperative use of low molecular heparin for anticoagulation,time for patients resumed ambulation were recorded.Multivariate logistic regression analysis was used to examine the relationship between these factors and to pick out the risk factors for DVT.Results Two hundred and twelve patients developed DVT after surgery.The incidence of DVT was 4.13 %.Logistic regression analysis showed that age ＞ 64 yr,body mass index≥25 kg/m2,complications such as diabetes and hypertension,history of phlebeurysma,triglyceride ≥ 1.7 mmol/L,D-Dimer≥ 500 μg/L,duration of surgery ＞ 4 h,general anesthesia,time for patients resumed ambulation ≥ 5 days were independent risk factors for DVT after orthopedic surgery.Conclusion Old age,obesity,history of phlebeurysma,complications such as diabetes and hypertension,high triglyceride and D-Dimer levels,long surgery,general anesthesia,prolonged duration of bed rest after operation are independent risk factors contributing to DVT in the lower extremity after orthopedic surgery. Key words: Risk factors ;  Venous thrombosis ;  Lower extremity ;  Bone diseases ;  Surgical procedures, operative