Biomechanical Evaluation of Cannulated Screw Optimization for Stabilization of Pauwels Type Femoral Neck Fractures

Triangular screw configuration (TSC) fixation is widely used in clinics for femoral neck fractures, and the appropriate positions of TSC fixation have not been fully described in the literature. This study investigated the optimal fixation of femoral neck fractures with TSC fixation under nonstandard Pauwels angles to determine the ideal position. To determine the optimal fracture line angle and cannulated screw positions, the Pauwels angle and Rotation and Translate variables were parametrically defined in the fracture line and cannulated screw positions. Considering the equivalent stresses on the fracture surfaces, the effectiveness values of the Rotation and Translate 1, 2 and 3 variables are weak, whereas the effectiveness value of the Pauwels angle is high. Considering the equivalent stress on the screws and that the variable value of Translates 1, 2 and 3 is 7 mm, it can be seen that the reverse triangulation configuration is better, and the Pauwels angle is approximately 54°. Among the parameters examined in the study, Pauwels angle was found to have the highest level of effectiveness on femoral neck fracture surfaces and screws. The findings in this study provide a solid basis for future research; however, further clinical research is warranted.