Radiological measurement and diagnosis of rotation displacement of pelvic fractures

Abstract

Objective To measure the sagittal rotation displacement of hemipelvis for determining the rotation displacement of pelvis on three dimensional section and further instructing closed reduction of pelvis fractures.Methods Sagittal rotation degree of hemipelvis was calculated by measuring the special radiological points and lines of a rational mathematical model created according to anatomic structure of pelvis and peri-and intra-operative pelvic frontal X-ray view.Ten cadaver pelvises without bony structure abnormality were selected and marked by lead line in bilateral anterior superior iliac spine and exterior edge of pubic symphysis.Hemipelvic rotation displacement in sagittal plane was simulated and modified pelvic frontal view was obtained in X-ray projection.Radiological data was measured and calculated by using radiological measuring software.Thereafter,feasibility and accuracy of the method discussed in the study were verified by statistical analysis.Results Distance of ipsilateral anterior superior iliac spine to exterior edge of ipsilateral pubic symphysis was measured and presented no statistical difference in both sides (P ＞0.05).As compared with the models of 20 degree of rotation of hemipelvis in sagittal plane desgined in this study,the calculated rotation degree presented no significant difference (P ＞ 0.05).Conclusion Quantified indicators of pelvic spatial displacement measured by special points and lines on X-ray films of modified pelvic frontal view put forwarded in study of pelvic anatomic structure and radiographic features guides reduction operation and effect judgment and benefits closed reduction of pelvic fractures. Key words: Pelvis; Fractures; Closed reduction