The effect of head trauma on fracture healing: biomechanical testing and finite element analysis.

OBJECTIVES We aimed to evaluate the effect of head trauma on fracture healing with biomechanical testing, to compare the results obtained from a femur model created by finite element analysis with experimental data, and to develop a finite element model that can be employed in femoral fractures. METHODS Twenty-two Wistar albino rats were randomized into two groups. The control group was subjected to femoral fracture followed by intramedullary fixation, whereas the head trauma group was subjected to femoral fracture followed by intramedullary fixation along with closed blunt head trauma. Bone sections obtained with computed tomography from rat femurs were transferred into a computer and a 3D mathematical model of femur was created. At the end of week 4, femurs were examined by biomechanical testing and finite element analysis. RESULTS The mean maximum fracture load was significantly higher in the head trauma group than in control group (p<0.05). Maximum strain values were also significantly high in the head trauma group (p<0.05). There was no significant difference between the groups with regard to maximum deformation (p>0.05). The head trauma group had significantly higher mean bending rigidity than the control group (p<0.05). The head trauma group showed no significant difference from the control group in terms of strain energy and elasticity module (p>0.05). There was no significant difference between experimental biomechanical test and finite element analysis (p>0.05). CONCLUSION Noninvasive methods such as finite element analysis are useful in examination of the mechanical structure of bones. Experimental biomechanical test and finite element analysis methods suggest that head trauma contributes to fracture healing.