For a complete articular acetabulum fracture to exist, which attachment must separate?

The presence of a complete articular acetabulum fracture is characterized by significant disruptions in the structure and stability of the hip joint. In this context, for a complete articular acetabulum fracture to occur, it is essential that specific anatomical attachments within the hip region are compromised.

The critical attachment that must separate for a complete fracture to be identified is the posterior ilium. The ilium is a large bone that forms the upper portion of the pelvis and is crucial for the integrity of the acetabulum, which is the socket of the hip joint. When a fracture occurs to the acetabulum, the posterior ilium's separation signifies a substantial injury that impacts not only the joint surface itself but also the surrounding stability and support structures of the pelvis.

The other attachments listed, while relevant in the context of hip and pelvic stability, do not represent the primary separation necessary for categorizing a complete articular acetabulum fracture. For instance, while the anterosuperior labrum and inferior obturator membrane may be involved in injuries surrounding the acetabulum, their separation does not alone confirm a complete fracture of the acetabulum. Similarly, separation at the superior pubis is not a defining characteristic of this specific type of fracture.

Therefore,