Anterior wall

The anterior wall fracture is a rare fracture pattern. The bone involved is commonly osteoporotic.

Fractures of the anterior wall are segmental fractures of the mid anterior column, are trapezoidal in shape and typically involve the anterior segment of the acetabulum.

Cranially, the fracture begins at the anterior border of the acetabulum, just below the anterior-inferior iliac spine. It crosses the articular surface, detaching the anterior articular facet and a variable portion of the acetabular fossa. Distally, the fracture traverses the superior margin of the obturator foramen transecting the pubic ramus.

On the internal surface, the fracture crosses the iliopectineal line 3-4 cm anterior to the SI joint. It descends along the quadrilateral surface below the pelvic brim, to the upper border of the obturator foramen and transecting the pubic ramus.

Displacement of the anterior wall fragment and marginal impaction of the acetabular roof articular cartilage are commonly associated with fractures of the anterior wall.

Further details on anterior wall fractures are provided in section Characteristics of elemental fracture types.

A summary of diagnosing the fracture classification based on x-ray and CT images is presented in section Patient assessment.

The section Radiology of the intact acetabulum provides explanation of the radiologic landmarks.

The section Characteristics of elemental fracture types provides further information on the radiology of anterior wall fractures.

X-ray image of marginal impaction, courtesy of TA Ferguson