The study aimed to compare the effectiveness of low-molecular-weight heparins (LMWH) followed by Rivaroxaban with no anticoagulant treatment in preventing deep vein thrombosis (DVT) after open reduction and internal fixation surgery (ORIF) for posterior cruciate ligament (PCL) avulsion fractures. This quasi-experimental study enrolled 37 patients with posterior cruciate ligament (PCL) avulsion fractures. Following surgery, four patients were excluded for not meeting the inclusion criteria, and the remaining 33 participants were allocated into Group A (n = 16) and Group B (n = 17). Surgical methods involved standard open reduction and internal fixation surgery (ORIF) protocols and anatomical alignment restoration using absorbable Bone Anchor Nails. Group A received prophylactic anticoagulation with LMWH followed by Rivaroxaban, while Group B did not received any anticoagulant. All patients received standard postoperative care included standardized rehabilitation protocols and monitoring for DVT using Color Doppler Ultrasound examinations. Patients underwent follow-up ultrasound examinations at 7 days and 1-month post-operation to assess DVT presence and condition. This comprehensive methodology allows for a thorough evaluation of the efficacy and safety of prophylactic anticoagulation in patients with PCL avulsion fractures and complications were observed between the two groups. The study included 33 patients who had undergone surgical treatment for PCL avulsion fractures, divided into Group A (LMWH followed by Rivaroxaban) and Group B (No anticoagulant treatment). No statistically significant differences were observed in the demographic and preoperative laboratory data between Group A (LMWH followed by Rivaroxaban) and Group B (no anticoagulation). Postoperatively, ESR, CRP, ALB, and Hb levels showed no significant differences between the two groups (P > 0.05). At 1 month postoperatively, the overall incidence of DVT was significantly lower in Group A (6.25%) than in Group B (35.29%) (P = 0.041). The percentage of DVT-free patients was 93.75% in Group A and 64.71% in Group B (P = 0.041). During the first seven postoperative days, the DVT incidence was 6.25% in Group A and 17.65% in Group B (P = 0.316), with a higher percentage of DVT-free patients in Group A (P = 0.041). From day 8 to 1 month postoperatively, no DVT cases were detected in Group A, while the incidence in Group B was 21.43% (P < 0.01). LMWH followed by Rivaroxaban significantly reduced DVT after PCL avulsion surgery. In addition, the D-D levels postoperatively were lower in the group of LMWH followed by Rivaroxaban group at 7 and 10 days after the operation. As for other inflammatory markers, there was no significant difference between the two groups. The reduction in DVT risk and D-Dimer levels suggests that the LMWH-rivaroxaban regimen may offer a clinically beneficial approach to anticoagulation therapy in patients undergoing PCL avulsion surgery.