Anterior Column Acetabular Fracture

Anterior column fractures make up to 5% of acetabular fractures. These fractures separate the anterior border of the innominate bone from the remaining ilium.

Several types of anterior column fractures have been described based on the location where the fracture plane exits the anterior aspect of the bone. However, all types cross the pelvic brim and result in a fracture of the inferior pubic ramus.

• Very low: Exit through the iliopectineal eminence. Can be distinguished from anterior wall fractures by the presence of an inferior pubic ramus fracture and a single break in the iliopectineal line.
• Low: Exit just below the anterior inferior iliac spine.
• Intermediate: Exit through the anterior superior iliac spine.
• High (shown above): Exit through the iliac crest.

Radiographs reveal disruption of the iliopectineal line where the anterior column fracture plane crosses the pelvic brim. This is best seen on the frontal and obturator oblique views. The femoral head moves medially and superiorly with the anterior column fragment.

The images above are from a patient with a high anterior column fracture. The radiograph reveals disruption of the iliopectineal line and a lucency through the iliac wing extending to the iliac crest. The CT images delineate the path of the fracture plane through the iliac crest and inferior pubic ramus.

References

• Rockwood and Green's Fractures in Adults (7th ed), pp 1478-1479.
• Mack LA, Harley JD, Winquist RA. CT of acetabular fractures: analysis of fracture patterns. AJR Am J Roentgenol. 1982 Mar;138(3):407-12.