To investigate the occurrence of deep venous thrombosis (DVT) in the perioperative period of patients with fracture distal to the knee, so that clinicians have a better understanding of the occurrence of DVT in the perioperative period of the fracture distal to the knee.

A retrospective analysis of the clinical data of 365 patients with distal knee fractures who underwent surgery in the Department of Orthopaedics Trauma, Xi′an Jiaotong University Medical College Red Cross Hospital from June 2014 to March 2018 was conducted. There were 213 males and 152 females, aged (45.05±15.24) years, with an age range of 17-83 years. Classification of fracture sites: 177 cases of tibiofibular shaft fracture, 130 cases of ankle fracture, and 58 cases of foot fracture. According to whether thrombosis occurred or not, the patients were divided into thrombotic group and non-thrombotic group before and after operation. There were 66 patients with thrombosis before operation, 299 patients without thrombosis before operation, 88 patients with thrombosis after operation, and 277 patients without thrombosis after operation. The incidence of thrombosis and the location of the thrombus were recorded. The sex, age, fracture site, ASA score, operation time, the time from injury to admission, the time from injury to surgery, intraoperative tourniquet time, intraoperative blood transfusion volume, intraoperative blood loss, intraoperative transfusion volume, hemoglobin volume at admission and 1 day after operation, D-dimer level at admission and 1 day after operation, multiple injuries, chronic hepatitis and medical diseases were analyzed. The measurement data of normal distribution and homogeneity of variance were expressed as mean±standard deviation (Mean±SD), the t test was used for comparison between two groups. The comparison of count data was performed by χ² test or Fisher exact probability method, and multivariate logistic regression analysis was performed on the risk factors affecting the occurrence of DVT in both lower extremities.

The preoperative DVT rate was 18.1% (66/365). In patients with thrombosis, distal thrombosis accounted for 93.94% (62/66), and mixed thrombosis accounted for 6.06% (4/66). The incidence of postoperative DVT was 24.1% (88/365). In patients with thrombosis, distal thrombosis accounted for 94.32% (83/88), proximal thrombosis accounted for 1.14% (1/88), and mixed thrombus accounted for 4.55% (4/88). Fracture site, ASA score, operation time, intraoperative tourniquet time, intraoperative blood transfusion volume, intraoperative blood loss, intraoperative transfusion volume were not statistically significant(P>0.05). Age ≥ 40 years (OR=2.691, 95% CI: 1.422-5.093, P=0.002), the time from injury to admission>3 days (OR=1.927, 95%CI: 1.072-3.463, P=0.028) were independent risk factors for DVT formation in fracture distal to the knee before operation. Age ≥ 40 years (OR=3.925, 95% CI: 2.161-7.129, P=0.000), the time from injury to surgery >5 days (OR=1.835, 95%CI: 1.080-3.119, P=0.025), D-dimer level at 1 day after operation (OR=1.191, 95%CI: 1.096-1.293, P=0.000), combined with multiple injuries (OR=1.981, 95%CI: 1.006-3.902, P=0.048), combined with coronary atherosclerotic heart disease (OR =2.692, 95%CI: 1.112-6.517, P=0.028) were independent risk factor for DVT formation after operation for fracture distal to the knee.

The occurrence of DVT before and after the fracture of the knee is mainly caused by distal thrombosis, and proximal thrombosis also occurs. Those patients aged≥40 years, combined with multiple injuries and coronary heart disease, should focus on preventing the occurrence of DVT. After the injury, the patient is immediately admitted to the hospital for DVT screening, and when the general condition allowed, shortening the preoperative waiting time can reduce the occurrence of DVT.

Fracture; Venous thrombosis; Risk factors