IMPORTANCE OF SIDEBAR-BONE SPACING DURING THE APPLICATION OF PERTROCHANTERIC FIXATOR ON FEMORAL INTERTROCHANTERIC FRACTURE MODEL; COMPARISON OF THE BIOMECHANICAL EFFECTS USING FINITE ELEMENT METHOD

Abstract

Many unwanted traumas occur in daily life, the result of which may be intertrochanteric fractures in the musculoskeletal system. An intertrochanteric femoral fracture is a serious trauma which can lead to pneumonia, pulmonary embolism or death. Therefore, accurate and stable fixation of these fractures is necessary. Schanz screws with a pertrochanteric fixator body are used for the stabilization of intertrochanteric fractures. The stability of fractures created by external fixators is dependent on the frame and bone interaction. The distance between the fixator body and the bone, called "sidebar-bone spacing", is one of the most important aspects of fracture stability. The primary objective in the treatment of these fractures is to maintain the stability of the fracture in the reduction position to allow early mobilization. In this study, an intertrochanteric femoral fracture was fixed with a pertrochanteric fixator, then the effect of sidebar-bone spacing on the fracture line under axial loading was analyzed using AnsysWorkbench software. Stress and strain values on the fracture line and schanz screws were calculated to understand this effect according to the von-Mises criteria. The sidebar-bone spacing was selected as 8, 6 and 4 cm. The von-Mises stress value on the fracture line decreased as the distance between the fixator body and the bone decreased, although strain values increased. In conclusion, decreasing the sidebar-bone spacing in the pertrochanteric fixator used on hip fractures provides stronger stabilization, and demonstrates safer axial loading.