ObjectiveTo compare the knee flexion degree after high-flexion versus standard total knee arthroplasty (TKA). MethodRelevant randomized controlled trials on comparison of knee flexion degree after high-flexion versus standard TKA were identified from Cochrane Library, PubMed, Embase, China National Knowledge Infrastructure from the establishment of these databases until October 2015. A systematic review was performed to compare knee flexion degree, knee function score and complications between the two types of prostheses. Analyses were conducted using RevMan version 5.2.0 software. ResultsTwenty-one studies were included in this Meta-analysis. The results showed that the knee flexion degree was higher in high-flexion group than that in the standard group[WMD=2.71°, 95%CI (0.96, 4.46)°, P=0.002]; while the difference was not significant leaving out six low-quality literatures[WMD=0.72°, 95%CI (-0.15, 1.60)°, P=0.10]. There was no significant difference in knee function score between the two groups[WMD=-0.54, 95%CI (-1.34, 0.25), P=0.18]. There was no significant difference in complications between the two groups[OR=0.99, 95%CI (0.53, 1.84), P=0.98]. ConclusionsThe important finding from the current study is that there is no evidence to support that the use of high-flexion prostheses is superior to the standard prostheses during total knee arthroplasty.