Mapping of 238 quadrilateral plate fractures with three-dimensional computed tomography.

PURPOSE: The primary goal of this study is to create a frequency map of a series of the quadrilateral plate fractures, explore the characteristics of fracture map and to further propose a new classification.

METHODS: We used a consecutive series of 238 quadrilateral plate fractures to create 3-dimensional reconstruction images, which were superimposed and oriented to fit a model hemipelvis template by aligning specific pelvis landmarks. Fracture lines were identified and traced to create a quadrilateral plate fracture map.

RESULTS: Fracture location corresponded with fracture line distribution. Of 238 fractures that met the criteria for inclusion, most fractures involved the "A + B" zone (n = 156; 65%), whereas the remaining minority of the fractures involved the "A" zone (n = 59; 25%) and the "B" zone (n = 23; 10%). Correspondingly the incidence of C-type fracture ("A + B"zone) was significantly higher than that of A-type fracture and B-type fracture. Additionally the most common pattern was demonstrated by coexisting fracture lines; nearly half (48%) of the fractures involved the upper section of the quadrilateral plate traversing both zones, 46% traced almost vertically to the arcuate line, and 25% extended to the posterior aspect. Furthermore, the high fracture line intensity (n = 172; 74%) formed a Gun-shaped pattern, which pointed to the ischial tuberosity.

CONCLUSIONS: The map shows that the comminution is prone to traverse the quadrilateral plate in the sagittal direction among nearly two-thirds of all fractures. Moreover, Surgically treated quadrilateral plate fractures display very common patterns. The most common pattern is the upper fracture in nearly half of the fractures. Knowledge of these patterns can aid surgeons during diagnosis, preoperative planning, and execution of surgical strategies.