The Quadrilateral Plate in Acetabular Fracture Surgery: What Is It and When Should It Be Addressed?

The quadrilateral plate (QP) is the relatively flat surface of bone in the true pelvis lying directly medial to the acetabulum. This surface is frequently involved in acetabular fractures. Elderly individuals, in particular, commonly sustain anterior column fractures with incomplete or complete posterior hemitransverse fracture lines with associated QP comminution. If QP fracture lines propagate through the superior weight-bearing surface of the acetabulum, the femoral head may displace medially, leading to poor outcomes if not addressed. Fortunately, the collective work of many orthopaedic surgeons has resulted in numerous effective methods for approaching, reducing, and stabilizing the QP and the diverse family of fractures which affect it. A thorough understanding of the QP, its anatomy, radiology, and techniques for fixation, is required to optimize patient outcomes.