Rivaroxaban versus low-molecular-weight heparin and fondaparinux for preventing deep vein thrombosis after total knee arthroplasty in high-altitude residents: a randomized controlled trial

High-altitude residence (defined as ≥ 1500 m above sea level) is associated with chronic hypoxia and increased thrombotic risk. This study aimed to evaluate the comparative efficacy and safety of rivaroxaban, low-molecular-weight heparin (LMWH), and fondaparinux for preventing deep vein thrombosis (DVT) after total knee arthroplasty (TKA) in long-term high-altitude residents.

In this randomized controlled trial, 90 high-altitude residents undergoing primary TKA were randomly assigned to one of three groups: rivaroxaban (group A), LMWH (group B), or fondaparinux (group C). The primary outcome was the incidence of postoperative DVT assessed by duplex ultrasonography on postoperative day 14. Secondary outcomes included coagulation indicators (PT, APTT, FIB, PLT, D-dimer), inflammatory markers (CRP, PCT, IL-6, ESR, WBC), knee circumference, intraoperative blood loss, and bleeding-related adverse events.

DVT incidence was 0% in the rivaroxaban group, compared with 16.7% in the LMWH group and 13.3% in the fondaparinux group (P = 0.016). On postoperative day 14, D-dimer levels were significantly lower in the rivaroxaban group than in LMWH (P < 0.001) and fondaparinux (P < 0.001) and lower in fondaparinux than LMWH (P < 0.001). PT and APTT were higher in the rivaroxaban group compared with LMWH (PT P < 0.001, APTT P = 0.012) and fondaparinux (PT P < 0.001, APTT P = 0.035). FIB and PLT showed no significant differences. CRP and PCT were significantly lower with rivaroxaban than LMWH (CRP P < 0.001, PCT P < 0.001) and fondaparinux (CRP P = 0.018, PCT P = 0.018), while IL-6, ESR, and WBC showed no group differences. Intraoperative blood loss and bleeding complications were comparable across groups.

Among high-altitude residents undergoing TKA, rivaroxaban demonstrated superior efficacy in preventing postoperative DVT and reducing inflammatory response without increasing bleeding risk. These findings contribute important evidence to guide anticoagulant selection in populations living at high altitude, who face unique thrombotic challenges due to chronic hypoxia.