Incidence of deep venous thrombosis (DVT) of lower extremity in patients undergoing surgeries for ankle fractures

Objective: To investigate the incidence of postoperative deep venous thrombosis (DVP) in patients undergoing surgeries for ankle fractures and identify the associated risk factors. Methods: This was a retrospective study. A total of 1451 patients undergoing surgery of ankle fractures from January 2016 to June 2019 were included. The inpatient medical record system was inquired for data collection, including demographics, comorbidities, injury and surgery-related data and laboratory biomarkers. DVT of lower extremity was diagnosed by routine doppler examination. Univariate analyses and multivariate logistic regression analyses were used to identify the independent risk factors. Results: Among the 1451 patients, DVT was confirmed in 38 cases, indicating an incidence of 2.6%. DVT involved both the operated and non-operated limbs in 8 patients (21.1%). DVT involved superficial femoral vein in 4 cases (6.6%), deep femoral vein in 2 (3.3%), popliteal vein in 5 (8.2%), posterior tibial vein in 11 (18.0%) and peroneal vein in 39 (63.9%). The median interval between operation and diagnosis of DVT was7 days. Six risk factors were identified to be independently associated with DVT, including age (10-year increase) (OR, 1.44), preoperative stay (delay of each day) (OR, 1.11), anesthesia (general vs regional) (OR, 3.51), lower hemoglobin level (OR, 2.02), total cholesterol >5.2mmol/L (OR, 3.20) and reduced lymphocyte count (OR, 3.16). Conclusion: These identified factors, although not easily modifiable, do help counsel patients about the risk of DVT and help individualized assessment of the risk factors and accordingly the risk stratification.