Measurement Discrepancy of Sagittal Parameters between Plain Radiography and 3D Computed Tomography in Thoracolumbar and Lumbar Fractures / 대한정형외과학회잡지

ABSTRACT

PURPOSE: For decision making in the management of vertebral fractures such as operation or not, sagittal parameters like Cobb angle and wedge compression ratio are important. Plain radiography had been the only image tool for measuring such parameters until 3D computed tomography (CT) became popular recently. In this study, we investigated the measurement discrepancy between plain radiography and 3D CT. MATERIALS AND METHODS: Plain radiography and 3D CT of 45 thoracolumbar and lumbar fracture patients (male=21, female=24) were evaluated. We measured sagittal angle and vertebral height on lateral radiography and sagittal CT. Sagittal angle was measured between the upper body and lower body of fractured vertebrae. Anterior and posterior heights were measured to assess anteriorposterior (AP) wedge ratio. RESULTS: The sagittal angle of plain radiography (13.1+/-14.3degrees) was significantly larger than that of 3D CT (8.2+/-13.0degrees) by 4.9degrees (p<0.001). AP wedge ratio of plain radiography was on average 65+/-17%, which was significantly lower than the 3D CT (73+/-17%) by 8% (p<0.001). The severer the initial kyphotic deformity, the more discrepancy of results between the two methods was observed. CONCLUSION: Significant discrepancy was observed in sagittal features of fractured vertebra between plain radiography and 3D CT. Measured values of plain radiography showed more kyphotic features of the fractured body.