Use of the obturator-outlet oblique view to guide percutaneous retrograde posterior column screw placement

In contrast to open reduction internal fixation, percutaneous fixation is a relatively new option for operative fixation of acetabular fractures. The techniques for percutaneous insertion of anterior and posterior column screws have been previously described. For technical aspects of retrograde percutaneous posterior column screws, much attention has been paid to the proper start point. However, descriptions of proper trajectory and end point have not been as clearly delineated. Understanding of posterior column anatomy and its radiographic correlates are fundamental in the safe placement of this screw. Herein, we present technical advice for acquisition and interpretation of fluoroscopic images needed to ensure a safe trajectory and end point in retrograde percutaneous posterior column screw placement. We highlight our steps to ensure correct placement in a small series.