Anterior column is larger, begins at iliac wing, extends to anterior portion of acetabulum and includes superior pubic ramus.
Posterior column begins at sciatic notch, extends to posterior acetabulum and ischium.
Posterior wall is larger than anterior wall
Acetabular rim is lateral portion of both walls
Quadrilateral plate is medial wall of the acetabulum
Dome of acetabulum is superior aspect and carries most of the weight
Classification:
Anterior pillar
Posterior pillar
Anterior wall
Posterior wall
Transverse
Combination of any of these
Radiography:
Iliopectineal line demarcates anterior column, begins at sciatic notch, travels along superior pubic ramus to symphysis pubis.
Ilioischial line demarcates posterior column, begins at sciatic notch to medial border of ischium, passes through acetabular teardrop. If it does not pass thorugh teardrop, posterior column is disrupted.
Iliac wing fracture in setting of acetabular injury indicates anterior column involvement.
Posterior wall is more visible than anterior wall on AP view
Obturator oblique view depicts posterior wall, and iliac oblique view depicts anterior wall.
Oblique Judet views are important in pillar fractures
Image Gallery:
Anterior and posterior pillar with floor fracture:Plain radiograph:
Also note symphysis pubis diastasis
Anterior and posterior pillar fracture with acetabular floor fracture: Axial CT correlation:
