A comparison of thrombosis in total knee arthroplasty with and without a tourniquet: a meta-analysis of randomized controlled trials

BACKGROUND: Tourniquets are widely used in total knee arthroplasty (TKA), but the issue of their safety remains controversial. Previous studies have focused on TKA blood loss, duration of surgery, and hemostatic drugs. The purpose of this meta-analysis was to analyze the effect of tourniquet use on postoperative deep venous thrombosis (DVT). METHODS: PubMed, SCOPUS, Web of Science, Embase, and the Cochrane Library were searched for randomized clinical trials published before April 17, 2020, that compared the effect of tourniquet use on postoperative DVT, knee circumference, D-dimers, and pain measured using the visual analog scale (VAS). RESULTS: Fourteen clinical trials that included 1321 unique participants were included in the meta-analysis. Among the total, 721 and 600 participants were randomized to the tourniquet and non-tourniquet groups, respectively. The incidence of postoperative thrombosis in the tourniquet group was significantly higher than in the non-tourniquet group (RR 2.30, 95% CI 1.51–3.49, P < 0.0001, I(2) = 0%). On the 1st, 3rd, and 5th to 21st days, and 3 to 6 weeks after surgery, the knee circumference difference of the tourniquet group was significantly larger than that of the non-tourniquet group (P < 0.05). However, 4 to 6 months after the surgery, no significant difference in knee circumference was found between the two groups (MD 0.14, 95% CI −0.02–0.31, P = 0.09, I(2) = 0%). The VAS score of the tourniquet group was higher than the non-tourniquet group on the 3rd and 5th days after surgery (P < 0.05). However, this difference was not significant (MD 0.31, 95% CI −0.05–0.66, P = 0.09, I(2) = 89%). CONCLUSION: Results of this meta-analysis indicate that tourniquet application could increase the incidence of postoperative DVT and aggravate postoperative pain and swelling in the short term. LEVEL OF EVIDENCE: Level III