Hi Mr. Peterrozenewman,

Thanks a lot again for your illuminating answers

2) Regarding question 2, there is now way actually to make surfaces smoother and change the geometry. Because there is a fracture plane on the lefts side of tibial head. And I think that nodal-normal-target option seems logical for this model,because target body is smoother than contact surface including with facets. Contact between medial load applicator and medial parts of bone are defined as bellow.

Contact between MA part and Medial load appliator


Contact between MP part and Medial load applicator


3) Regarding interface treatment, I tried to use really small element size in the contact area. But because of some initial penetrations and errors in positioning load applicator, I selected adjust to touch to be sure that contact and target surfaces are initially in touch. However, still I can not fully understand why the result are very different when Add offset-no ramp option is selected. How could we be sure that an appropriate interface treatment method is selected? Is it enough to compare the outcomes with experimental data and select the option with closer outcomes? Is it interesting that Adjust to touch option has 6% error but by selecting Add offset no ramp options results are 20% smaller than experimental ones.  Do you think that contact refinement could be helpful, to get the same results for both interface treatment methods? 

I am grateful for all of your kind attentions in advance.

Best regards, Shabnam Samsami