An imaging study of the compressed area, bony fragment area, and the total fracture-involved area in thoracolumbar burst fractures.

STUDY DESIGN:Imaging study. SUMMARY OF BACKGROUND DATA:X-ray and computed tomography (CT) sagittal reconstruction images are used to evaluate the stability of the spine. However, we did not know the extent of difference between them. OBJECTIVE:The aim of the study was to compare the differences seen in thoracolumbar burst fractures on lateral radiographs and CT sagittal reconstruction images and investigate their clinical relevance. MATERIALS AND METHODS:Lateral radiographs and CT sagittal reconstruction images of 45 patients with thoracolumbar burst fractures were used to record the following measurements: the compressed area of the fractured vertebrae, from lateral radiographs, and the sagittal compressed area, bony fragment area, and total fracture-involved area, from CT sagittal reconstruction images. RESULTS:The percentage of compressed area of fractured vertebrae was 29.32±13.80% on lateral radiographs and 27.93±12.21% on CT sagittal reconstruction images; there was no significant difference between them (P>0.05). The percentage of total fracture-involved area was 53.20±20.64% on CT sagittal reconstruction images, higher than the compressed area measured on lateral radiographs (P<0.01) and CT sagittal reconstruction images (P<0.01). The percentage of bony fragment area was 25.27±15.18% on CT sagittal reconstruction images; there was no significant relationship between bony fragment area and the compressed area (r=0.1258, P>0.05). CONCLUSIONS:The compressed area of fractured vertebrae on lateral radiographs could not represent the fracture-involved area and underestimated the total fracture-involved area. We suggested that the above 3 parameters could be easily obtained on CT sagittal reconstruction images, which might be better for assessing the potential instability of the thoracolumbar burst fracture and could become a valuable and indispensable examination for therapeutic decision making.