Ideal plate screw configuration in femoral shaft fractures: 3D finite element analysis

Abstract

Background/Aim: Plate screw fixation is an important method in femoral shaft fractures. Although there are many studies on plate screw fixation, the ideal plate screw configuration has not yet been determined. In our study, we investigated the optimal plate-screw configuration in femoral shaft fractures using the 3D finite element analysis method. Methods: A fracture model was created by removing the segment from the femur model obtained from 3D computed tomography scanning. Five different fixation models were designed using a 4.5 mm diameter steel locked femoral shaft plate and different screw configurations. Screws with double cortex locks of 4.5 mm in width were used in different configurations. To evaluate the effect of screw diameter, a 5.5 mm diameter screw with a double cortex lock was used in one model. Static linear analyses of these prepared Finite Element models were performed using Ansys Workbench 2020 R2 Finite Elements software. Results: The maximum stresses on the plate at the fracture sites were 156 MPa at 200 N, and 546 MPa at 700 N in model 1, 274 MPa at 200 N, and 784 MPa at 700 N in Model 2, 274 MPa at 200 N, and 959 MPa at 700 N in Model 3, 389 MPa at 200 N, and 1118 MPa at 700 N in Model 4, and 200 N is 274 MPa, and 961 MPa at 700 N in Model 5. Conclusion: The stress on the plate in the fracture area increases in parallel with the increase in screw diameter, plate length and plate working distance. Filling all screw holes does not alter the stress on the plate at the fracture line level.