Abstract: Abstract： Objective To explore the biomechanical difference between the treatment of unstable femoral
intertrochanteric fractures with common proximal femoral anti rotation nail and bone cement augmented proximal femoral
anti rotation nail. Methods A healthy volunteer was selected to import the CT data into the software of Mimics 19.0 and
Geomagic studio 2017 to extract and optimize the three-dimensional model of the right femur. The Solid works 2017 software
was used to draw the internal fixation model and assemble it with the femur model according to the standard operation
technology, and import it into Hypermesh 14.0 software in step format to cut the bone according to Evans V type of
intertrochanteric fracture. The part of the cancellous bone on the surface of the proximal spiral blade was redefined as the
bone cement component, which was stored as A and B models respectively. The material parameters, boundary conditions
and applied loads were set, which were stored as K files and imported into LS-DYNA software for solution. The blade
cutting, inversion and rotation of proximal femoral neck bone mass and Von Mises stress and displacement distribution were
observed. Results In the model of cement augmented proximal femoral anti rotation nail, the cutting degree of the screw
blade was lighter, the osteotomy and rotation angle of the femoral head and neck block were less, and the displacement of the
fracture end was less. Conclusion The treatment of Evans V type intertrochanteric fracture with bone cement augmented
proximal femoral anti rotation nail in elderly has better biomechanical effect than that of the common proximal femoral anti
rotation nail.

Key words: intertrochanteric fractur, proximal femoral nail anti-rotation, bone cement, finite element