Presentation
Motor vehicle collision with rotational instability of the left hemipelvis.
Patient Data

The symphysis pubis and left sacroiliac joint are widened, no definite fracture.



Normal pelvic ligaments.
Image credit: Henry Gray (Gray's Anatomy)
Case Discussion
A subsequent CT scan (not shown) showed that the anterior left sacroiliac joint was widened but that the posterior SI joint was intact, indicating that the left anterior sacroiliac, sacrospinous and sacrotuberous ligaments were torn but that the posterior sacroiliac ligament was intact. These findings indicate an anteroposterior compression II injury using the Young and Burgess classification of pelvic ring fractures.