RESUMO
Objective To study the wear condition of rotating hinge knee prosthesis (RHKP) during horizontal walking gait, and provide technical references for wear prediction and clinical application of this kind of prosthesis. Methods A finite element wear model of RHKP was established based on the standard ISO 14243, and the simulation results including the wear distribution and mass wear rate of tibiofemoral joint surface were compared with the results from in vitro experiments on the same type of prosthesis. Results The mass wear rate of the polyethylene insert was 26.01 mg/MC (million cycle)from finite element analysis (FEA) and (30.06±1.21) mg/MC from in vitro experiments, and the mass wear rate of the upper surface of polyethene insert from FEA was about 3.3 times that of the lower surface. The wear area obtained by FEA was basically consistent with that obtained by in vitro wear measurement. The main wear area was symmetrically distributed in the middle and back of the upper surface. Conclusions The mass wear rate of RHKP, as a semi-restrictive prosthesis, is obviously higher than that of primary total knee joint prosthesis. More attention should be paid to wear test and evaluation of RHKP.