Perioperative combined intravenous and intra-articular tranexamic acid does not increase venous thromboembolism risk after total knee arthroplasty in plateau areas: a randomized controlled trial

After total knee arthroplasty (TKA), rivaroxaban is often used to prevent venous thromboembolism (VTE), while tranexamic acid (TXA) is used to reduce perioperative bleeding. However, plateau hypoxia may affect coagulation. We assessed whether combined intravenous and intra-articular TXA increases VTE risk in plateau TKA patients. This single-center, prospective, randomized, double-blind, pilot controlled trial was conducted at altitude greater than 3500 m. Fifty unilateral TKA patients were randomized to experimental (intravenous + intra-articular TXA) or control (intravenous TXA alone). All received rivaroxaban for 14 days. Primary outcome was new-onset DVT (deep vein thrombosis) or PE (Pulmonary Embolism) at day 3; secondary outcomes included thromboelastography (TEG) and coagulation parameters at 6 h, 1, 2, and 3 days. No VTE occurred in either group. Nonthrombotic ultrasound findings (intermuscular vein dilation with blood stasis) were observed in 9/25 (36%) of the experimental group and 13/25 (52%) of the control group, with no between-group difference (P = 0.254). TEG parameters showed no significant differences, except for a transiently lower D-dimer in the experimental group on day 1 (P < 0.001), though clinical relevance is unclear. Hb and Hct declined less in the experimental group at all time points (P < 0.05), suggesting reduced blood loss. In plateau TKA patients, adding intra-articular TXA to intravenous TXA did not increase short-term VTE risk. These preliminary findings suggest combined TXA with rivaroxaban may be well tolerated in this population.