The experimental study of pubic diastasis and sacroiliac disruption

Objective:To investigate the relationship between diastasis of the symphysis pubis and changes of sacroiliac joints,to predict the standard of disruption of sacroiliac joints through the changes of public symphysis. Methods: The study was performed in 8 specimens of Chinese cadaveric pelvises. The pelvic viscera were removed and parietal pelvic fascia remained. Bilateral open-book pelvic injuries were created in cadaveric specimens by directly disrupting the public symphysis,bilateral anterior sacroiliac ligament,and sacrospinous and sacrotuberous ligaments. When the public diastasis was 1cm ,3cm,5cm,7cm respectively,Sacroiliac disruption was calculated using data acquired from pelvic computerized axial tomography (CT) by CAD measure software. Results: The sacroiliac disruption increased with the public diastasis increasing. When the public diastasis was 0cm,1cm,3cm,5cm and 7cm respectively,the sacroiliac disruption was 6.93±0.44mm,9.63±0.21mm,11.64±0.33mm ,14.35±0.29mm on the left and 6.91±0.44mm,9.63±0.19mm,11.63±0.20mm,14.30±0.49mm on the right respectively. Correlation between the change in pubic diastasis and the sacroiliac disruption were evaluated using linear regression analysis. R(left)=0.991,r(right)=0.992 ,P0.01. The left sacroiliac disruption(mm)=5.777+1.214× pubic diastasis(cm). The right sacroiliac disruption(mm)=5.784+1.209× pubic diastasis(cm). Conclusions: The sacroiliac disruption increased with the public diastasis increasing. The sacroiliac joints changes could be predicted though the distance of diastasis of public symphysis and provide instruction to clinical treatment.