The aim of the study is to create a new more accurate method of femur part modelling by using the finite element method. According to this new method, a femur part is treated as a complex structure composed of trabecular bone (internal part) and cortical bone (external part). The internal part is modelled as a scaffold, thus the external part is modelled as a coat (i.e. covering). Applying the programme ABAQUS, there were created four numerical models of trabecular femur part (regular shell bar-connected scaffold, regular solid bar-connected scaffold, irregular shell bar-connected scaffold, irregular solid bar-connected scaffold) and four numerical models of femur part composed of trabecular and cortical bone areas (regular shell bar-connected scaffold covered by shell coat, regular solid bar-connected scaffold covered by solid coat, irregular shell bar-connected scaffold covered by shell coat, irregular solid bar-connected scaffold covered by solid coat). Applying similar boundary conditions and similar load affected by muscles’ forces and external moments, presented numerical models had been tested. Considering stress (strain) fields obtained from numerical researches of presented models, there were drawn conclusions about influence of material nonlinearity and geometry nonlinearity and application of proposed new method in clinical biomechanics.