To compare the stability of two types of cannulated screws for femoral neck fracture in high altitude area with three-dimensional finite element technique.

CT images of 1 normal femoral neck were obtained and the femoral neck fracture model was prepared by 3-Matic Research 13.0. The finite element models of oblique triangle and inverted triangle of hollow screw were established respectively. The finite element models were loaded at 500 N,1 000 N, 1 500 N and 2 100 N, respectively. The Von Mises peak stress and displacement of cannulated screws and the stress distribution of femoral head were observed and recorded.

Under the same load, the maximum displacement and the maximum VonMises stress of the screw with oblique triangle configuration is smaller than that of the screw with inverted triangle configuration. The stress concentration range of femoral head in oblique triangle configuration was smaller than that in inverted triangle configuration. The overall maximum displacement of femur in oblique triangle configuration was less than that in inverted triangle configuration. The maximum VonMises stress of femur in oblique triangle was higher than that in inverted triangle.

Under the same load, compared with the traditional inverted triangle configuration, the oblique triangle configuration is more consistent with the normal anatomical characteristics of femoral neck, the stress distribution of each screw is more reasonable, the fixation of fracture is stronger, and it can effectively avoid the occurrence of complications such as fracture failure and internal fixation cutting out.