LAUSR

Purpose Although a tourniquet can effectively control intraoperative blood loss and offer clear surgical field in total knee arthroplasty (TKA), its optimal usage has been controversial. The aim of this research was to perform a systematic review and meta-analysis to compare and explore the best application of a tourniquet in TKA. Methods MEDLINE, PubMed, EMBASE, the Cochrane Library, Wanfang database, and Web of Science were searched for randomized controlled trials (RCTs) comparing the four different strategies of tourniquet application in TKA. In Group I, a tourniquet was not used and was called the non-tourniquet (NT) group. In Group II, a tourniquet was only used during the cementation of implants and was called the specific duration tourniquet (SDT) group. In Group III, the tourniquet was only released before wound closure to control the bleeding sources and was called the majority duration tourniquet (MDT) group. In Group IV, a tourniquet was used throughout the procedure, from skin incision to wound closure and was called the whole duration tourniquet (WDT) group. Results Forty-six RCTs were included in this systematic review and meta-analysis. In a comparison between the NT and WDT groups (25 RCTs), intraoperative blood loss (IBL) ( P  = 0.0001) and range of motion (ROM) ( P  = 0.0001) were significantly increased in the NT group, while the visual analog score (VAS) ( P  = 0.0001), rate of deep vein thrombosis (DVT) ( P  = 0.01), and all complications (AC) ( P  = 0.0001) were significantly decreased in the NT group. In a comparison between the SDT and WDT groups (10 RCTs), IBL ( P  = 0.0001), TBL ( P  = 0.009), and ROM ( P  = 0.0001) were significantly increased in the SDT group, while thigh pain ( P  = 0.04) and the rate of DVT ( P  = 0.03) were significantly decreased in the SDT group. There were no significant differences between the MDT and WDT groups (12 RCTs) except for the rate of all complications ( P  = 0.01). Conclusion Despite the decrease in IBL with a tourniquet, no difference was found in TBL. In conclusion, not using a tourniquet or only using it during the cementation of implants was preferable based on the faster functional recovery, lower rate of DVTs and complications compared with using a tourniquet throughout the TKA procedure. Level of evidence I.