The most important finding of this meta-analysis was that patients undergoing THA who received topical application of FS had higher blood transfusion rates and sustained lower hemoglobin levels compared with application of TXA in the early postoperative period. However, the total calculated blood loss showed no significant differences between the two groups. Furthermore, our meta-analysis demonstrated that there was no significant difference in the rate of complications between the topical FS group and the TXA group during the THA.
TXA has been widely used to reduce blood loss and transfusion rates in THA and TKA[23-24]. Moreover, several clinical trials and meta-analyses have demonstrated that topical FS is effective and safe in reducing blood loss and transfusion in hip and knee surgery[25-27]. A previous meta-analysis compared the effect of topical FS and intravenous administration of TXA on blood loss after TKA, and its pooled results indicated that TXA use resulted in a significantly lower incidence of blood transfusion and higher hemoglobin level. However, there was no significant difference in blood loss or in the rate of complications between the two groups. Whether the two pharmacological interventions have the same results in THA as during TKA is still controversial. Several clinical trials on the application of topical FS and TXA in THA have been implemented[19-22]. Kearns et al. concluded that the use of TXA significantly reduced blood-transfusion requirements and preserved higher hemoglobin levels in patients undergoing THA compared with topical FS. Mahmood et al. conducted a clinical trial that obtained similar outcomes. In contrast, McConnell et al. did not find a significant difference in blood loss or transfusion rate between FS and TXA groups. Our meta-analysis results indicated that there was a lower blood transfusion rate and a higher hemoglobin level in the TXA group.
Due to the large exposure of the surgical area and the activation of fibrinolysis, perioperative bleeding is a significant concern in major orthopedic surgery, which often results in anemia[28-30]. Acute anemia can lead to myocardial infarction and heart failure. Therefore, in order to reduce blood loss and improve safety during THA, the surgical significance of TXA is widely recognized, especially in joint replacement. A series of randomized clinical trials have been implemented to study the relative benefits and potential risks of using TXA. Severe anemia is frequently corrected by means of allogeneic blood transfusion. In the current meta-analysis, patients treated with TXA had higher postoperative hemoglobin levels than FS-treated patients. However, the current meta-analysis demonstrated that there was no significant difference in total blood loss between the two groups. The method used to calculate blood loss in the included studies was not the same, which may lead to the calculated blood loss differing from the actual amount. In the study by McConnell et al. the method of blood loss calculation was chosen in light of previous work. The total blood loss consisted of swabs and suction drainage, which can lead to substantial underestimation of the actual loss. Whether a blood transfusion is required depends on the postoperative hemoglobin level. We believe that the higher requirements for blood transfusion in patients treated with FS were associated with lower postoperative hemoglobin levels. Mahmood et al.and Jordan et al. reported that the use of TXA can reduce the total amount of blood loss in patients undergoing THA compared to the application of FS, although the difference was not statistically significant. Nevertheless, the outcome of one included study indicated that blood loss was significantly reduced in the group receiving TXA compared to the group receiving FS. Mahmood et al. reported that 2 mL of FS was sprayed around the short external rotators after the prosthesis was implanted and the hip reduced, and a further 2 mL in superficial layers after fascia lata closure in the FS group. However, patients treated with TXA received 1 mg TXA intravenously on induction of anesthesia. Obviously, different methods were used to apply the hemostatic measures and calculate total blood loss, which may be one reason why no significant reduction in blood loss was observed in the patients receiving TXA compared with those patients receiving FS.
Perioperative complications in THA include deep vein thrombosis (DVT), pulmonary embolism (PE), wound infection, hematoma, periprosthetic fracture, and dislocation. Generally speaking, DVT and PE are common postoperative complications and can even lead to the risk of death in TKA and THA. In our study, we were unable to carry out a meta-analysis of the incidence of DVT and PE owing to the small sample size and insufficient data, but only performed a meta-analysis of the overall complication rate. We found no significant difference in the complication rate between the group receiving TXA compared with the group receiving FS. Moreover, numerous studies and meta-analyses have indicated that topical FS or intravenous/topical administration of TXA does not increase the prevalence of DVT or PE during THA[27,33-36]. Wound infection is also a complication of THA, and in spite of the low prevalence of infection, it is a devastating complication. However, due to the small sample size and insufficient data in the included study, we could not conduct a meta-analysis to draw an exact conclusion. Moreover, subgroup analyses of the different complications were not carried out owing to the lack of sufficient data required for further confirmation.
There were several limitations to this meta-analysis: (1) two of the included studies were non-RCTs. As we all know, due to the large selection bias of non-RCTs, our meta-analysis result may involve a great deal of heterogeneity.(2) The included studies were not the same in terms of surgical time, technique, methods of intervention, and postoperative measures. (3) Due to the small sample size and insufficient data of each primary study, as well as the significant heterogeneity in postoperative hemoglobin decline and complication rate, we did not carry out subgroup analysis to draw a firm conclusion. (4) The endpoints for evaluating the efficacy of THA, including duration of hospital stay, functional scores, rehabilitation, range of motion, cost and postoperative swelling, were not analyzed because these data were not included in each primary study. (5) Due to the limitation of retrospective studies, the outcome may have a less robust analysis. (6) There was publication bias.