Accessing 3D Location of Standing Pelvis: Relative Position of Sacral Plateau and Acetabular Cavities versus Pelvis

Figure 4

The sagittal X-ray of the standing patient does not represent a pure profile of the pelvis: the hip axis 𝑌_𝑝 connecting the femoral head centers is slanted versus the transverse radiographic axis 𝑌₀, and the frame center 𝑂_𝑝 is not centered versus the radiographic set up. The table presents pelvic tilting and incidence angles measured on sagittal X-ray and the 3D global absolute position of pelvis versus fixed frame and relative position of sacral plate with respect to pelvis (global and relative positions include angular orientations and linear offsets between frame centers).