Elliptic crack behavior emanating from the cement mantle of the total hip prosthesis

Damage accumulation and failure in the cement polymethylmethacrylate (PMMA) is the most prominent in a cemented total hip arthroplasty (THA) leading to eventual implant loosening. In this study, we used the three-dimensional finite element method (FEM) to analyze and calculate the three modes (I, II and III) of the stress intensity factor (SIF) of elliptic crack in the cement mantle for different sizes, orientation and location of crack according to different patient activities. From obtained results, we show that the opening crack mode is proportional to the stress applied on the damaged part (compression or traction). The risk of crack failure in the anterior region of the proximal part is more important and causes a danger of fracture of cement whose the value of the SIF reached exceeds the intrinsic resistance of the material. The study of the daily patient activities shows us that the climbing stairs represents the maximum value of SIF.