Finite element analysis on the mechanical effect of a roughened stem for cemented hip prosthesis

The bonding strength of stem/cement interfaces is crucial for the long-term performance of total hip prosthesis. For improving the fixation strength, the metallic prostheses have been textured proximally, or roughened. To investigate the mechanical effect of roughened stem, this paper proposed an analysis model integrating the finite element analysis and strength experiments of metal/cement interfaces. For this, a series of tensile and shearing tests were conducted to assess the interfacial bonding strength of the metal and cement. The cemented femoral models with different interfacial properties were employed to investigate the effect of the roughened stem on the mechanical performance under the gait loadings. Current results show that the stem with roughened surface can enhance the bonding strength with bone cement and provide a loading path from stem to cement and bone in more even way, causing the stress distribution more uniform and smooth within the cemented prosthetic structure.