Acetabulum Anterior Wall, Column, Hemi-Transverse
An anterior wall fracture is rare. The fracture does not go to the obturator foramen and the ischiopubic ramus is not fractured; the fracture does not extend to the obturator foramen. There will be disruption of the iliopectineal line. Disruption of the iliopectineal line could be seen at two points. The ilioischial line is intact. The anterior wall fracture is best seen in the obturator view. An anterior wall fracture of the acetabulum is usually associated with anterior subluxation or dislocation of the hip. An anterior column fracture is usually associated with a disruption of the iliopectineal line and the ilioischial line will be intact. A fracture is seen in the obturator view and the fracture will involve the obturator foramen. The isciopubic ramus is usually fractured. This fracture is more common in old patients. The physician should check for an associated medial wall fracture in addition to the anterior column fracture. There are several types of fractures that are based on the location where the fracture exits the iliac bone anteriorly.
A high anterior column fracture exits at the iliac crest. An intermediate anterior column fracture exits at the anterior superior iliac spine. A low anterior column fracture exits below the anterior inferior iliac spine. Both anterior wall and anterior column fractures of the acetabulum are treated by the anterior approach of the acetabulum, such as the ilioinguinal approach. The anterior injury can be anterior column or an anterior wall fracture. The posterior injury is a hemi-transverse fracture. The posterior hemi-transverse fracture is identical to the posterior half of the transverse fracture and it starts from the anterior acetabular fracture to the posterior innominate bone. Anterior displacement occurs more than posterior displacement. The femoral head subluxes or dislocates anteriorly. A portion of the acetabulum is still attached to the iliac wing and to the axial skeleton. Therefore, this fracture is NOT an associated BOTH column fracture. In associated BOTH column fractures, the acetabulum is disconnected from the axial skeleton and the acetabulum is a floating acetabulum.
CT scans are very helpful. They will show fractures of both columns; however, the anterior column will have a coronal fracture. Coronal means column fracture seen anteriorly. Posteriorly, a different fracture will be seen. The physician will see a vertical or sagittal fracture in the posterior column (hemi-transverse in posterior column). A transverse fracture is NOT transverse! A transverse fracture is a vertical fracture, so the vertical line is visible in the posterior column, meaning that it is a half-transverse fracture in the posterior column.
