How to obtain and identify the acetabular anterior column axial view projection in patients?

This study aims at sharing our experience as how to obtain and identify axial view image of the acetabular anterior column in patients.

Pelvic computed tomography data of six normal adults were used to reconstruct three-dimensional (3D) models. The transparency of each 3D model was downgraded at the view perpendicular to the cross section of the anterior column axis to simulate the anterior column axial view image. Fluoroscopy was performed in all patients to obtain the anterior column axial view image in the operating room. Each fluoroscopic image was compared with the corresponding simulation image to analyze potential anatomic landmarks that were helpful to identify the translucent area (projection of the screw path) in the patients.

To obtain ideal anterior column axial fluoroscopic image, the patient should be positioned supine with the leg of "abnormal side" straight and contralateral side flexion, abduction, and external rotation; the C-arm machine should be placed at the caudal end of the operation table with the C-arm fluoroscopic intensifier first positioned at the pelvic lateral view and then tilted approximately 30° toward the "abnormal side" and rotated approximately 45° toward the caudal end of the operation table. To identify the translucent area on the anterior column axial view fluoroscopic image obtained from the patient, the greater sciatic notch, the true pelvis edge, and the acetabulum should be identified first and the translucent area is located in the area surrounded by these three anatomic landmarks.