Introduction

Functioning of joint prostheses is accompanied by a continuous formation of wear particles and their accumulation in surrounding tissues. The impact of microroughnesses of joint prosthesis friction units may bring about chemical bond breakage and free-radical generation on a newly-formed wear surface. Wear particles of orthopedic alloys are capable to produce free radicals, and Co-Cr-Mo alloy particles are especially active. Free radicals generated by wear particles can cause oxidation and reduced wear resistance of polyethylene. Oxidised polyethylene particles stimulate the activity and release of bone-resorbing cytokines by human monocytes/macrophages. The ability of free radicals to cause damage to surrounding tissues and implant components makes it necessary to estimate comprehensively the radical-generating activity of wear particles of different orthopedic materials and develop the ways of its inhibition.