Fig. 4
From: Outcomes after surgical treatment of acetabular fractures: a review
Line drawing and (A, b) and anteroposterior (B), iliac oblique (C) radiographs of the “gull-sign.” The fragment is a partial fracture of the posterior column (A) not including the ischial tuberosity; it involves the posterior portion of the quadrilateral surface, the ischial spine, and the roof is hinged inwards. This displacement of the posterior quadrilateral surface manifests as a re-duplication of the ilioischial line and the rotated roof segment, adjacent to the intact roof, appears as a gull in flight. Permission was granted for utilization of this figure in this review