UHMWPE ; Electron beam irradiation ; Mechanical characteristics
Abstract
Ultra-High Molecular Weight Polyethylene (UHMWPE) has been used successfully for articulating surfaces of joint
endoprostheses, i.e. cup linear on acetabular component of total hip arthroplasty, in orthopaedics for over three
decades. Although numerous attempts have been performed to characterize and to improve the polymeric material,
i.e. to reduce the molecular degradation due to in vivo oxidation, the effect of electron beam irradiation on loaddisplacement
characteristics of UHMWPE has not been reported clearly. The aim of the current study is to quantify
the effect of the electron beam irradiation with alteration of the amount of irradiation on the mechanical characteristics
of the polymeric material. In this work, monotonic uniaxial and small punch tests were conducted to examine
the relative capabilities of four samples irradiated with electron beam at 0, 50, 100, and 150 kGy, based on a
prediction of mechanical behavior of the UHMWPE materials. Load-displacement behaviors of UHMWPE were not
changed significantly by electron beam irradiation less than 150 kGy although the stiffness of irradiated UHMWPE
decreased gradually. Conclusively, changes of stiffness and deflection by irradiation were not significant. However,
load characteristics were significantly changed by irradiation.