A Case-control Study Of The Role Of Postoperative Levels Of Neutrophil Extracellular Traps In Deep Vein Thrombosis After Total Knee Arthroplasty

Chapter 1 A case-control study of the role of postoperative levels of neutrophil extracellular traps in deep vein thrombosis after total knee arthroplastyObjective To investigate the role of circulating neutrophil extracellular traps (NETs) levels in the postoperative formation of deep vein thrombosis (DVT) in patients undergoing total knee arthroplasty (TKA).Methods Circulating NETs levels were measured preoperatively and on postoperative days 1,3,and 7 in 30 patients diagnosed with DVT by venography after TKA and 30 controls from May 2014 to July 2015.Results In patients with DVT, the mean circulating NETs levels were significantly higher on postoperative days 1 and 3 compared with those in the non-DVT group (postoperative day 1,1.598±0.067 vs.1.212±0.037, P<0.001; postoperative day 3, 1.305±0.044 vs.1.167±0.032, P<0.05). ROC curve analysis revealed the inferior sensitivity and specificity of NETs levels on postoperative day 3 compared with postoperative day 1. Area under the curve (AUC) postoperative day 1 was 0.828±0.053 (95%CI:0.722,0.933, P<0.001); AUC postoperative day 3 was 0.677±0.070 (95%CI: 0.541,0.814, P<0.05). The cutoff point for NETs levels on postoperative day 1 was 1.294, with a sensitivity of 80%, a specificity of 80%, a positive predictive value of 80%, and a negative predictive value of 80%. After logistic regression, the NETs level on post- operative day 1 was considered an independent predictor of DVT (NETs level on postoperative day 1>1.294, OR:24.08,95%CI:4.94,117.28, P<0.01).Conclusion High circulating NETs levels are associated with DVT in patients who undergo TKA. NETs may serve as a potential biological marker to delineate patients undergoing TKA who are most at risk for DVT.Chapter 2 Exploring immunological mechanisms of thrombus formation after arthroplastyVenous thromboembolism (VTE), which includes deep venous thrombosis (DVT) and pulmonary embolism (PE), is a serious, potentially life-threatening complication after major orthopedic surgery. Some patients can occur Post-thrombotic syndrome (PTS), leading to lower limb ulcer, necrosis and pigmentation. A new potential mechanism of thrombus formation had been raised in recent years, which was the immune system had played an essential role in it. This article will overview the role of immune system in thrombus formation after total knee or hip arthroplasty.