[Safety and efficacy of rivaroxaban for prevention of deep vein thrombosis in patients with preoperative abnormal D-dimer after total knee arthroplasty].

OBJECTIVE

To evaluate the safety and efficacy of rivaroxaban for prevention of deep vein thrombosis (DVT) in patients with preoperative abnormal D-dimer after total knee arthroplasty (TKA).

METHODS

Between August and September 2013, 60 consecutive patients with varus knee osteoarthritis undergoing unilateral TKA were enrolled in the study. According to the preoperative D-dimer level, the patients were divided into 2 groups: D-dimer normal group (control group, n = 41) and D-dimer abnormal group (test group, n = 19). No significant difference was found in gender, age, body mass index, and preoperative knee range of motion between 2 groups (P > 0.05). All patients underwent conventional primary TKA and anticoagulation therapy with rivaroxaban to prevent DVT. The tourniquet use time, postoperative hospitalization time, and total hospitalization time were compared between 2 groups. At 1, 3, and 5 days after operation, prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), fibrinogen (FIB), and D-dimer were measured. Wound complications and DVT were observed.

RESULTS

The postoperative hospitalization time of the test group was significantly longer than that of the control group (t = 2.327, P = 0.031), while the tourniquet use time and total hospitalization time showed no significant difference between 2 groups (P > 0.05). All the patients were followed up 6-8 months (mean, 7.2 months). Wound complications occurred in 3 cases (7.3%) of the control group and in 2 cases (10.5%) of the test group, showing no significant difference (χ2 = 0.175, P = 0.676). Color ultrasonography showed no pulmonary embolism and DVT at 6 weeks after TKA. There were significant differences in PT, TT, and FIB between at pre- and post-TKA in the same group, but no significant difference was found between 2 groups. The APTT and D-dimer had significant differences between at pre- and post-TKA in the same group, and between groups. There was no significant interaction effect between time and group for each index.

CONCLUSION

Preoperative abnormal D-dimer level should not be regarded as a contraindication for TKA. The risks of DVT and wound complications in patients with abnormal D-dimer level are similar to patients with normal D-dimer level using rivaroxaban administration after TKA. It is unnecessary to conventional monitor D-dimer and other coagulation and hemorrhage laboratory tests in the patients after TKA.