Abstract: ［Abstract］Objective〖HTSS〗To assess the predictive value of D-dimer dynamic changes in deep vein thrombosis(DVT) after hip replacement.
 〖WTHZ〗Methods〖HTSS〗A total of 94 patients undergoing hip replacement for hip fracture were selected. Plasma D-dimer values were monitored before surgery on the day of surgery and on days 1, 2, 3, 6, 9 and 12 after surgery, all patients underwent color Doppler ultrasonography of the deep veins before and 2 and 5 days after operation. When the D-dimer rised significantly, double-lower deep vein color Doppler examinations were performed immediately. In cases where color Doppler could not be diagnosed, double lower limb angiography was performed. ROC curve was draw to evaluate the predictive value of D-dimer dynamics for DVT.
 〖WTHZ〗Results〖HTSS〗DVT occurred in 20 of 94 patients(21.3%). The level of D-dimer in the two groups increased and then decreased, and reached the peak on the third day after operation. The change range of thrombus group was large, and the interaction among groups, time points and time points was statistically significant(P＜0.05 or P＜0.01). The median time from operation date to diagnosis of DVT was 3 days. On the third day after operation, D-dimer level showed moderate accuracy, and the area under the curve was 0.856(95%CI: 0.740-0.971, P＜0.001). The cut-off value of 0.696 was 6.23 mg/L.
 〖WTHZ〗Conclusion〖HTSS〗Dynamic monitoring of D-dimer level is of great significance for DVT prediction. D-dimer level on day 3 can be used as a predictor of DVT.

Key words: arthroplasty, replacement, hip；venous thrombosis, D-dimer