Stoppa approach for open reduction and internal fixation of acetabular fracture. A, Incision. B, Retraction of rectus abdominis muscle. C, Wet sponge packed into retropubic space to protect the urinary bladder. D, Dissection of periosteum from the superior pubic bone. (From AO Surgery Reference, www.aosurgery.org. Copyright by AO Spine International, Switzerland.) E, Identification of the corona mortis vessels. F, Dissection of the iliopectineal arch from the bone. G, Elevation of the periosteum and obturator internus to expose the quadrilateral surface. H, Placement of Hohmann retractors to expose acetabulum. (Redrawn from AO Foundation, Davos Platz, Switzerland.) SEE TECHNIQUE 56.1.