Risk factors for ecchymosis in patients receiving rivaroxaban for thromboprophylaxis after total knee arthroplasty: a retrospective cohort study

Personalized delayed anticoagulation therapy alleviates postoperative bleeding in total knee arthroplasty (TKA) patients

Purpose

Ecchymosis is one of the most common complications following total knee arthroplasty (TKA), which is closely related to postoperative bleeding. However, it is still controversial whether anticoagulation treatment should be continued for postoperative ecchymosis patients. We suppose that personalized delayed anticoagulation therapy could be beneficial for decreasing postoperative bleeding.

Methods

A total of 201 TKA patients were retrospectively included in this study, among whom ecchymosis patients received drug anticoagulation treatment 1-2 days later than usual, while nonecchymosis patients received regular drug anticoagulation treatment. The perioperative blood loss, coagulation state, fibrinolytic state and complications were collected and analyzed.

Results

Eighty-nine patients (44.3%) developed ecchymosis within 3 days after TKA. There were no differences in baseline characteristics between the two groups. In the ecchymosis group, higher K values and lower calculated coagulation index values were observed in thromboelastography, along with greater total blood loss and a more significant decrease in haemoglobin levels on postoperative Day 1 (POD1) compared to the nonecchymosis group. Additionally, the ecchymosis patients exhibited higher levels of fibrinogen degradation products and D-dimer (D-D) on POD1, with no differences noted on POD3, indicating that patients with ecchymosis are in a relatively hypocoagulable and hyperfibrinolytic state compared to those without ecchymosis. Therefore, the delayed anticoagulation treatment proved beneficial for correcting these postoperative conditions. No statistically significant differences were found between the two groups in postoperative complications, demonstrating that delayed anticoagulation treatment is safe.

Conclusion

Patients with ecchymosis exhibited a relatively hypocoagulable and hyperfibrinolytic state with a stronger tendency for postoperative bleeding. Delayed anticoagulation in ecchymosis patients could effectively prevent further exacerbation of postoperative bleeding by avoiding sustained hypocoagulable and hyperfibrinolysis states. Personalized delayed anticoagulation therapy could be beneficial for managing postoperative ecchymosis for TKA patients.

Level of Evidence

Level IV.

The Role of Anti-Factor Xa Activity in the Management of Ecchymosis in Patients Receiving Rivaroxaban after Total Knee Arthroplasty

This study aims to evaluate the efficacy of anti-factor Xa activity (aFXa) in predicting ecchymosis after total knee arthroplasty (TKA). One hundred and two unilateral primary TKA patients were recruited consecutively in this prospective observational study. Participants received rivaroxaban (10 mg p.o. qd) from postoperative day 1 (POD1) to POD35 and were divided into a non-ecchymosis group (group A) and an ecchymosis group (group B). AFXa was assessed as the primary outcome on POD1 and POD3. Prothrombin time (PT), activated partial thromboplastin time (APTT) and thromboelastography (TEG) were recorded both preoperatively and postoperatively (on POD1 and POD3). Other outcomes, including venous thromboembolism (VTE), blood loss and wound complications were also collected and compared. As a result, 27.5% of the participants (n = 28) were allocated into group B. Demographic data were comparable between the two groups. The aFXa levels in group B were significantly higher than those in group A on POD1 and POD3, and the aFXa level was assessed as an independent risk factor for ecchymosis. The cut-off value of aFXa was determined to be 121.38 ng/mL at maximal Youden index, associated with area under the receiver operating characteristics curve of 0.67. Group B experienced significantly more blood loss and wound complications than group A. No statistical difference was detected regarding PT, APTT and TEG parameters. AFXa is a promising parameter to predict ecchymosis after TKA. Patients with aFXa > 121.38 ng/mL should be considered as high-risk population for postoperative ecchymosis and may require intense monitoring or dosage modification of anticoagulants.

Does living at high altitude increase the risk of bleeding events after total knee arthroplasty? A retrospective cohort study

OBJECTIVE

Post-operative bleeding after total knee arthroplasty (TKA) is a frequent cause of post-operative complications. This study compared blood loss and indicators of coagulation and fibrinolysis between TKA patients living at low or high altitudes.

METHODS

We retrospectively analyzed 120 patients at our institution who underwent primary TKA from May 2019 to March 2020, and we divided them into those living in areas about 500 m or > 3000 m above sea level. We compared the primary outcome of total blood loss between them. We also compared them in terms of several secondary outcomes: coagulation and fibrinolysis parameters, platelet count, reduction in hemoglobin, hidden blood loss, intra-operative blood loss, transfusion rate, and incidence of thromboembolic events and other complications.

RESULTS

Total blood loss was significantly higher in the high-altitude group than in the low-altitude group (mean, 748.2 mL [95% CI, 658.5-837.9] vs 556.6 mL [95% CI, 496.0-617.1]; p = 0.001). The high-altitude group also showed significantly longer activated partial thromboplastin time, prothrombin time, and thrombin time before surgery and on post-operative day one, as well as increased levels of fibrinogen/fibrin degradation product on post-operative days one and three. Ecchymosis was significantly more frequent in the high-altitude group (41.7 vs 21.7%; relative risk (RR) = 1.923 [95% CI, 1.091-3.389]; p = 0.019). The two groups showed similar transfusion rates, and none of the patients experienced venous thromboembolism, pulmonary embolism, or infection.

CONCLUSION

High altitude may alter coagulation and fibrinolysis parameters in a way that increases risk of blood loss after TKA. Such patients may benefit from special management to avoid bleeding events.