OBTAIN A: Outcome Benefits of Tranexamic Acid in Hip Arthroplasty. A randomised double blinded controlled trial

Background We examined whether the blood conserving effect of tranexamic acid in total hip arthroplasty using the direct anterior approach, translates to an effect on functional outcomes in the perioperative period. Methods We conducted a single centre randomized, double blinded, placebo controlled trial. 101 patients were randomised to receive either tranexamic acid or an equivalent volume of normal saline. The primary outcome measure was thigh swelling. Secondary outcome measures included, visual analogue pain score, timed up and go test, a 10 meter walk test and length of stay. Blood loss and the incidence of blood transfusions was also recorded. Results There were no statistically significant differences between the primary outcome of thigh swelling. There was also no statistically significant difference in the secondary outcome measures of post operative pain nor mobility. There was a significant reduction in length of stay for those that received TXA 3.58 days (0.84) compared with the control group 4.27 days (0.98) (p< 0.001). There was significantly less intraoperative blood loss observed in the TXA group (0.460L SD 0.228) compared with the control group (0.687L SD 0.283L) (p < 0.001). The estimated blood loss was also significantly less in the TXA group (1.084L SD 0.440) compared with the control group (1.394 L SD 0.426). Interpretation TXA is an effective agent in reducing blood loss in THR using the anterior approach. The blood conserving effect of TXA was not associated with improved post operative recovery across the measures of pain and mobility. Administration of TXA may have a positive effect on reducing the duration of inpatient stays.