Quadrilateral plate fractures of the acetabulum: Proposition for a novel classification system

Background: Currently, there is no definition or classification system for quadrilateral plate (QLP) fractures; the aim was to anatomically and radiologically characterise the QLP, propose a definition and classify QLP fractures. Methods: This study included an anatomical component and a radiological component. The anatomical study aimed at defining the characteristics of the QLP; the QLP was identified using four articulating bony pelvis specimens. A titanium mesh was placed on the specimens' quadrilateral surface; standard anteroposterior and oblique views were obtained, and axial CT images, to determine the radiological landmarks. The radiological study included the review of images of patients with QLP fractures; fractures involving the QLP were identified in a series of 609 consecutive patients with acetabular fractures. Results: We considered QLP fractures where the QLP is separated from both columns of the acetabulum; this was found in 16% (98 cases). They were mostly encountered with associated both columns fractures (60 cases; 61%), Separation of the QLP could be complete or incomplete, or simple or comminuted, so QLP fractures were divided into three types: QLP1, simple with incomplete separation; QLP2, comminuted with incomplete separation; QLP3, comminuted with complete separation (QLP4), simple with complete separation. Conclusion: The QLP was characterised, and a definition and classification system; Cairo University Hospitals (CUH) Classification was proposed for these fractures. We believe that this classification may prove useful in the future for the identification and management of these fractures. (c) 2017 Elsevier Ltd. All rights reserved.