Inclusion criteria: A total of 1540 patients aged 60 years or older who were
diagnosed with OA or RA before undergoing TJA in our hospital between January
2017 and December 2021.
Exclusion criteria: (1) a history of VTE (3 cases); (2) use of anticoagulation
medications (aspirin, clopidogrel, warfarin, rivaroxaban, dabigatran): atrial
fibrillation (4 cases), coronary heart disease (CHD) patients with installed
stents and anticoagulant therapy (5 cases); (3) joint infection: knee joint (6
cases); (4) tuberculosis of the joint (10 cases); (5) tumors of the joints (10
cases); (6) thrombophilia genetic disorders (0 cases); (7) no preoperative lower
extremity ultrasound records (111 cases); (8) no routine blood test records (0
cases). Finally, a total of 1391 patients were enrolled.