To evaluate the preventive effect of anticoagulant on venous thromboembolism after knee arthroscopy.

Five databases including PubMed, Excerpta Medica Database(EMbase), Cochrane Library, China National Knowledge Infrastructure (CNKI) and Wanfang Database were searched. All randomized controlled trials (RCTs) comparing prophylacticuse of anticoagulant drugs and no use of anticoagulant drugs after knee arthroscopywere retrieved from the database establishment to September 2022.Trials involving the use of anticoagulants in the control group or nonpharmacologic anticoagulation in the experimental group were excluded. Two researchers independently screened the literature. The quality of the included literatures was evaluated and data were extracted. The incidence of pulmonary embolism (PE), symptomatic DVT, and asymptomatic proximal DVT of the lower extremities were selected as the observation indicators for efficacy, and the incidence of severe major bleeding and minor bleeding were selected as the observation indicators for safety. RevMan 5.4 software was used for meta-analysis.

Eight RCTS involving 4 302 patients were included. There was no statistically significant difference in the incidence of pulmonary embolism (PE) between the prophylactic anticoagulation group and the non-anticoagulation group after knee arthroscopy [relative risk (RR)=1.36, 95% confidence interval (CI)(0.37, 4.97), P=0.64]. The incidence of symptomatic DVT in prophylactic anticoagulation group was significantly lower than that in non-anticoagulation group[RR=0.32, 95%CI(0.16, 0.63), P=0.001]. The incidence of asymptomatic proximal DVT in prophylactic anticoagulation group was significantly lower than that in non-anticoagulation group [RR=0.17, 95%CI (0.06, 0.48), P=0.0007]. There was no significant difference in the incidence of major hemorrhage between the two groups [RR=1.44, 95%CI(0.25, 8.14), P=0.68]. The incidence of minor hemorrhage in prophylactic anticoagulation group was higher than that in non-anticoagulation group, and the difference was statistically significant [RR=1.47, 95%CI(1.11, 1.94), P=0.006].

Prophylactic use of anticoagulants after knee arthroscopy can effectively reduce the incidence of symptomatic DVT and asymptomatic proximal DVT without increasing the risk of severe bleeding. However, the incidence of PE, symptomatic DVT and asymptomatic proximal DVT after knee arthroscopy is low regardless of whether anticoagulation is used or not. Clinicians should fully consider the risk factors of patients when deciding whether to take anticoagulation.