Hip prostheses computational modeling: Mechanical behavior of a femoral stem associated with different constraint materials and configurations

The paper deals with finite element (FE) models of femoral stems aimed at supporting fatigue mechanical tests according to Medical Devices Standards. A basic model was created in agreement with the ISO7206-4:2010 requirements and used to investigate a certain number of varied configurations: the abduction and the flexion angle were varied in the range 2° 15° and 2° 13° respectively, and the constraint level in the range (3080)mm. Once the most critical configuration had been identified, femur-like FE models were created to investigate it in a context closer and closer to the in-vivo scenario: the models, in fact, were based on a femur-like fixture, and on various materials to simulate cement and cancellous bone. Both Titanium and Co-Cr-Mo alloys were used for the stem. For both alloys the highest stresses were found in correspondence with a 80mmconstraint and a more soft cancellous bone; higher risky deflection was estimated for theTitanium stem. The great potential of FE methodology and analysis is here commented, as a valid support to experimental tests. © 2012 Taylor & Francis Group.