Background:Placement of closed suction drains after total knee arthroplasty is an age-old practice; however, benefits and disadvantages of this procedure remain disputable in various studies.Methods:We performed an electronic database search in Medline/PubMed, the Cochrane Library, and Embase to retrieve publications with respect to this issue and then screened reference lists of related articles manually to obtain any additional ones. Randomized controlled trials (RCTs) evaluating the use of closed suction drains after primary total knee arthroplasty were eligible for this study. Useful data were extracted to calculate the pooled risk ratios (RRs) or weighted mean differences (WMDs) as well as corresponding 95% confidence intervals (CIs) as summary estimates.Results:Nineteen RCTs were included in the quantitative analysis. Compared with patients in the nondrainage group, those in the drainage group were significantly correlated with a decreased need of dressing change (RR=0.31, 95% CI 0.12 to 0.79, P=.015) but an increased risk of homologous transfusion (RR=1.38, 95% CI: 1.04-1.83) and longer time to regain straight-leg raising (WMD=0.97 d, 95% CI: 0.48-1.46). Two groups showed no significant difference in total blood loss, hemoglobin drop, superficial wound infection, prosthetic joint infection, formation of deep vein thrombosis, duration of hospital stay, and range of movement.Conclusions:Based on this analysis, the use of closed suction drains after total knee arthroplasty is probably not superior to no drains for most outcome measures and therefore surgeons may wish to reconsider the routine use of this empirical practice until there is further evidence.