Figure 3: Representative clinical example (patient 1) of the gold-standard measurement method. (a) Identification of four points as the four corners (point 1: top of the acetabular rim; point 2: top of the posterior column; point 3: inferior portion of the ischial spine; point 4: bottom of the acetabular rim), (b) Determination of the quadrilateral plate plane, (c) Placement of cutting plane 1 from point 1 to point 2, perpendicular to the quadrilateral plate plane, and of plane 2 from point 3 to point 4, perpendicular to the quadrilateral plate plane, (d) Definition of the acetabular region (ivory) by the region cut by the quadrilateral plate plane, cutting plane 1 and cutting plane 2, (e) Calculation of the gold-standard posterior acetabular surface area (Y'' = 2340.5856 mm^[2]), shown in orange, by marking the area using the brush tool in the 3-matic software program, (f) Calculation of the fracture fragment area (X'' = 737.8588 mm^[2]), shown in orange, by marking the area using the brush tool in the 3-matic software program. The percentage of posterior wall involvement is calculated as: (X''/Y'') × 100% = (737.8588/2340.5856) × 100% = 32%.