ObjectiveTo compare the early clinical outcome of GenesisⅡ high-flexion versus standard prostheses in total knee arthroplasty (TKA), and evaluate whether high-flexion prostheses can improve the postoperative range of motion (ROM). MethodsBetween September 2007 and December 2011, 80 patients (85 knees) consecutively underwent posterior cruciate-sacrificing TKA with GenesisⅡ systems. Finally, we reviewed 60 patients (60 knees) including 32 knees in high-flexion group and 28 knees in standard group. The follow-up time was 2.7 years in average. The postoperative knee ROM and the rate of complication of the two groups were evaluated. ResultsThe mean postoperative knee ROM of 32 knees was 112.8° in the high-flexion group and was 108.9° in the standard group. The mean postoperative HSS score was 86.6 and 84.2, respectively. The postoperative knee ROM, hospital for special surgery (HSS) score and the rate of complication did not show significant difference between the two groups. ConclusionThe high-flexion prosthesis is no better than the ordinary prosthesis in terms of the range of motion. We need more mid to long-term studies to do further research.