Background:Tranexamic acid (TXA) is an antifibrinolytic drug widely used as a blood-sparing technique in total knee arthroplasty (TKA), and it is usually administrated by intravenous or intraarticular injection. Recently, the oral form of TXA has been applied in TKA patients. However, there is no final consensus regarding the effectiveness and safety of oral TXA. The purpose of this systematic review and meta-analysis of randomized controlled trials (RCTs) was to evaluate the efficacy and safety of oral TXA versus control for blood loss after TKA.Methods:We searched PubMed, Embase, Medline, Web of Science, and Cochrane Library databases for relevant studies through August 2017. The mean difference (MD) of total blood loss, hemoglobin (Hb) drop, hematocrit (Hct), drain output, and risk difference (RD) of transfusion rate and thromboembolic complications in the TXA and control groups were pooled throughout the study. The outcomes were pooled by Stata 12.0.Results:A total of 5 RCTs (608 patients) were included in this study. All the included studies were randomized and the quality of included studies was relatively high. The pooled results indicated that the oral TXA group had significantly less Hb drop (standardized mean difference [SMD], -0.936; 95% confidence intervals [CI], -1.118,-0.754), Hct drop (SMD, -0.693; 95% CI, -1.113, -0.274), and drain output (SMD, -0.793; 95% CI, -0.959, -0.628) than the control group. No statistically significant differences were found in transfusion rate and the incidence of thromboembolic complications between the 2 groups. Total blood loss could not be evaluated for the insufficient date.Conclusions:Our meta-analysis suggested that the administration of oral TXA provided significantly better results with respect to Hb drop, Hct drop, and drain output without increasing the transfusion rate and the risk of thromboembolic complications after TKA. Nevertheless, our current study with some limitations such as the small sample size only provided limited quality of evidence, confirmation from further meta-analysis with large-scale, well-designed RCTs is required.