Gun barrel view of the anterior pelvic ring for percutaneous anterior column or superior pubic ramus screw placement.

Background: Traditionally, operative fixation of pelvic and acetabular injuries involves complex approaches and significant complications. Accelerated rehabilitation, decreased soft tissue stripping and decreased wound complications are several benefits driving a recent interest in percutaneous fixation. We describe a new fluoroscopic view to guide the placement of screws within the anterior pelvic ring.

Methods: Twenty retrograde anterior pelvic ring screws were percutaneously placed in ten cadaveric specimens. Arranging a standard C-arm in a position similar to obtaining a lateral hip image, with angles of 54° ± 2° beam to body, 75° ± 5° of reverse cantilever and 14° ± 6° of outlet, a gun barrel view of the anterior pelvic ring is identified. Fluoroscopic images were taken, and the hemipelvi were harvested to examine the dimensions of the anterior pelvic ring and inspected for any cortical or articular perforation.

Results: The minimum cranial-to-caudal distance in the anterior pelvic ring was 9 mm (range 6.5-12 mm), and the minimum anterior-to-posterior dimension was 9 mm (range 5-15 mm). All but 2 screws were completely confined within the osseous corridors. Identifiable on final fluoroscopic evaluation, one screw perforated the psoas groove and a second perforated the acetabular dome. Overall, 90 % of our screws were accurately and safely placed, upon the first attempt, within the anterior pelvic ring using the described gun barrel view.

Conclusion: Employing either open reduction, or following a closed or percutaneous reduction, the anterior pelvic ring gun barrel view can reproducibly guide safe placement of anterior pelvic ring screw fixation.

Level Of Evidence: IV.