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).
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.
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.
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.