FINITE-ELEMENT MODELING - PREDICTOR OF IMPLANT SURVIVAL

The cancellous bone stresses surrounding proximal femoral prostheses w ere investigated using the finite element method and the results corre lated with clinical subsidence data for similar implant configurations . The finite element study has shown that press-fit prostheses generat e significantly higher cancellous bone stresses than bonded (cemented and HA coated) prostheses. The cancellous bone stresses surrounding pr ess-fit implants are sensitive to the coefficient of friction, with up to a 60% decrease observed when the coefficient of friction was incre ased from 0 to 0.4. Resecting the femoral neck generally increased the cancellous bone stresses however varying the thickness of the cement mantle had little or no effect. Good correlation was found between the finite element results and the clinically measured subsidence data. I mplant configurations generating higher cancellous bone stresses were those which subsided the most. This observation suggests that it may b e possible to use the initial cancellous bone stresses to predict the likelihood of migration and hence late aseptic loosening.