Objective:To investigate the safety and risk factors of the internal fixations of different accesses in treating hip fracture under C-shaped arm in combined surgery of preoperative CT and 3D reconstruction.Methods:A total of 150 patients with hip fracture underwent preoperative computed tomography(CT)and three dimensional(3D)reconstruction in The Second People's Hospital of Huishan District of Wuxi City from January 2017 to June 2023 were selected,and they were divided into anterior access group,posterior access group,retrograde access group,direct access group and mixed access group according to different modes of surgery access and internal fixation under C-shaped arm,with 30 cases in each group.The incidence rate of complication of hip fracture in each group was calculated as statistical method,and logistic regression was used to analyze the high risk factors of affecting surgical safety,and the advantages and disadvantages of each access mode.Results:The incidence rates of the complication of hip fracture of patients of the anterior,posterior,retrograde,direct and mixed groups were respectively 36.67%,56.67%,80.00%,103.33%and 30.00%,and the difference of the incidence rates of complications among different groups was significantly(x2=11.35,P<0.05),and the incidence rates of them indicated that mixed access group