Study On The Positioning Method Of Anterior Superior Iliac Spine And Public Symphysis For Femoral Head Mid-point

Objective: To calculate the geometric relationship among the anterior superior iliac spine(point A),pubic symphysis mid-point(point B)and femoral head mid-point(point D)on the radiograph of pelvis,and to obtain the geometric method of locating the femoral head mid-point with point A and point B.Methods:Selected 100 pelvic radiographs from 2018 to 2019 in radiology department of Hospital,50 cases were males and 50 cases were females,marked points A,B and D on the measurement software,connection between the anterior superior iliac spine and pubic symphysis mid-point was segment AB,intersected segment AB at point C from point D,measured the length of segment AB,AC and CD.Set two positioning parameters a and b: a=AC/AB,b=CD/AB.Collected every data and made statistical analysis.Results: Mean value of a in male group was 0.429±0.025,which in female group was 0.413±0.026,a significantly statistical difference between the two groups;Mean value of b in male group was 0.155±0.023,which in female group was 0.140±0.023,a significantly statistical difference between the two groups.The mathematical method for locating point D by points A and B was divided into two steps: 1.AC=AB*a(male a=0.429;female a=0.413),therebylocating point D by points A and B;2.CD=AB*b(male b=0.155;female a=0.140),thereby locating point D with point C.Conclusion: The femoral head mid-point can be located accurately and conveniently by the anterior superior iliac spine and pubic symphysis,there are significant statistical differences between male and female positioning parameters a and b.