Computerized Axial Tomography of Pelvic Ring Fractures

Abstract

The radiographs of all patients admitted to the Naval Hospital, Oakland with the diagnosis of pelvic trauma from 1981 through 1985 were reviewed. Thirty-one patients sustained single or double vertical ring fractures. Fifteen of these patients underwent both plain radiography and Computerized Axial Tomographic (CAT) scans in the evaluation of their pelvic injuries. The CAT scans of these pelvic injuries aided in detecting occult sacroiliac disruptions, determining the extent of posterior ring comminution, evaluating possible extension of the pelvic fractures into the acetabulum, assessing pelvic ring stability, and demonstrating soft-tissue injuries within the pelvis. Six pelvic injuries were diagnosed as single vertical breaks in the pelvic ring and nine were diagnosed as double vertical breaks in the pelvic ring by plain radiographs. CAT scanning demonstrated occult posterior ring disruptions in four patients which led to to the reclassification of their injuries to double vertical fractures. CAT scanning also demonstrated significant degress of sacral comminution in five patients which altered surgical treatment plans in all five patients. Two fractures were classified as unstable based on marked sacral comminution demonstrated on CAT scan. Extension of the pelvic ring fractures ito the acetabulum was suggested on plain radiographs in three patients and was excluded by review of the CAT scans in these patients. Significant intrapelvic hematomas were demonstrated in three patients and urine extravasation into the hip joint from a bladder laceration was seen in one patient with the CAT scan. We concluded that the indications for CAT scanning of pelvic fractures are: 1) single breaks in the pelvic ring in which a significant posterior ring injury is suspected but cannot be confirmed by plain radiography; 2) double vertical fractures of the pelvis in which plain radiographs or physical examination cannot exclusively demonstrate the stability of the pelvis; 3) evaluation of fracture pattern extension into the articular portion of the acetabulum; 4) injuries to the pelvis that are under consideration for open reduction and internal fixation; and 5) evaluation of intrapelvic soft-tissue injuries.