BackgroundThe problem of opioid addiction after total hip arthroplasty (THA) has been widely concerned. Tranexamic acid (TXA) has been shown to be effective in reducing blood loss for patients undergoing THA, but few studies focus on its alleviation of postoperative local pain symptoms. The purpose of this study was to investigate whether topical TXA could reduce early postoperative hip pain for primary THA patients, thereby reducing the use of opioids, and whether local pain is related to inflammatory response.MethodsIn this prospective randomized controlled study, we randomly divided 161 patients into a topical group (n= 79) and an intravenous group (n= 82). Hip pain was assessed using the visual analogue scale (VAS) score within three days after surgery and tramadol was used for pain relief when necessary. Inflammatory markers such as high-sensitivity C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), interleukin-6 (IL-6), total blood loss and hemoglobin drop were assessed by hematologic tests. The primary outcomes included the VAS score and dose of tramadol from the first to the third day after surgery. The secondary outcomes included the inflammatory markers level, total blood loss and complications.ResultsThe pain score and inflammation markers level on the first day in the topical TXA group were significantly lower than those in the intravenous TXA group (P< 0.05). The correlation analysis showed that the VAS score on the first day after surgery was positively correlated with the inflammation markers level (P< 0.05). The tramadol dose for topical group was lower than intravenous group on the first and second day after surgery. There were no differences in total blood loss between the two groups (640.60 ± 188.12 ml vs. 634.20 ± 187.85 ml,P= 0.06). There was no difference in the incidence of complications.ConclusionTopical use of TXA could relieve the local pain symptoms and reduce opioid consumption compared with intravenous use for patients undergoing primary THA by reduce the early postoperative inflammatory response.Trial registrationThe trial was registered at the China Clinical Trial Registry (ChiCTR2100052396) on 10/24/2021.