RESUMO
<p><b>OBJECTIVE</b>To compare the clinical efficacy of using tranexamic acid in different ways to reduce the hidden blood loss in patients who receiving total hip arthroplasty (THA).</p><p><b>METHODS</b>Totally 68 patients with osteonecrosis of the femeral head treated by total hip arthroplasty in our hospital from February 2010 to July 2015 were randomly divided into the intravenous drip group (group A) and the topical application group (group B). In group A, there were 19 males and 15 females, with an average age of (62.0±6.4) years old, preoperative average hemoglobin was (121.30±8.15) g/L, average Hematocrit was (0.470±0.039) L/L. In group B, there were 18 males and 16 females, with an average age of (64.0±7.5) years old, preoperative average hemoglobin was (125.28±9.37) g/L, average Hematocrit was (0.490±0.041) L/L. The operation incision were performed through the posterolateral approach and the normal operation mode, biological prosthesis was selected. Through different ways the tranexamic acid was used to control of intraoperative and postoperative bleeding. Tranexamic acid was intra articular injection as a dose of 10 mg/kg 10 min to patient before anesthesia in intravenous drip group. In topic group, 3 g of tranexamic acid was dissolved in 120 ml saline and divided into three equal parts, then two pieces of gauze were immersed in 40 ml tranexamic acid solution. One gauze with 40 ml tranexamic acid was used to soak the acetabulum for 5 minutes after the acetabular preparation, another gauze was inserted in the femoral canal for 5 minutes after femoral canal broach preparation. The remaining 40 ml tranexamic acid fluid was injected into the hip joint after fascia closure. Place the drainage tube and clip it for 3 hours. Hemoglobin (Hb) and Hematocrit (Hct) were recorded at 72 hours after operation. The total blood loss, dominant blood loss, and hidden blood loss were calculated.</p><p><b>RESULTS</b>In group A, postoperative hemoglobin difference before and after operation was (32.34±7.42) g/L, total blood loss was (833.6±81.4) ml, the hidden blood loss was (276.3±57.9) ml, red blood cell volume was (10.1±1.4) L/L;In group B, hemoglobin difference before and after operation was (28.2±6.1) g/L, total blood loss was (792.5±61.8) ml, the hidden blood loss was (297.5±50.3) ml, red blood cell volume was (9.2±1.2) L/L. There was no statistical significance about those aspect (>0.05). Compared of blood coagulation function between two groups, in group A: PT (12.78±2.03) s, APTT (34.27±3.91) s, INR (32.34±7.42); and in group B: PT (13.17±2.19) s, APTT (32.36±3.18) s, INR (28.24±6.14). There was no significant differences also (>0.05).</p><p><b>CONCLUSIONS</b>Compared with intravenous application, topical application of tranexamic acid could also effectively reduce total blood loss and hidden blood loss, postoperative blood transfusion rate in primary total hip arthroplasty, while does not increase the risk of DVT.</p>