Comparison of the biomechanical effects of pertrochanteric fixator and dynamic hip screw on an intertrochanteric femoral fracture using the finite element method

Abstract

Background: This study was conducted to examine and compare the pertrochanteric fixator (PTF) and dynamic hip screw (DHS).

Methods: AnsysWorkbench, a commercial finite element based program, was used to investigate the biomechanical parameters of femoral fractures and implants. The human femoral model was scanned and a femoral intertrochanteric fracture was created. Von Mises stress, von Mises strain, and shear and deformation forces on the upper and lower parts of the fracture line; and the von Mises stress, von Mises strain parameters of the screws and implant bodies during axial loading were calculated and compared.

Results: It was determined that the magnitude of displacement forces along the fracture line was lower in PTF. Regarding the von Mises stress and von Mises strain values on the implant bodies, the DHS body had higher levels compared with the PTF body.

Conclusion: This study demonstrated that PTF is more favorable than DHS for early axial loading and ambulation.

Keywords: Intertrochanteric fractures; devices; dynamic hip screw; external fixator.