MRI appearance of ACL rupture
The most characteristic appearance of ACL rupture is absence or discontinuity of the fibers. Usually, a tear of the ACL is an all-or-none phenomenon where few identifiable fibers are left, or at best an irregular or wavy contour of the ligament remains. Although sagittal images can be used to diagnose the majority of ACL ruptures, the ACL is oriented obliquely relative to routine imaging planes, and therefore should be evaluated on all images in all planes.
Avulsion fracture of the tibial spine is another typical appearance of ACL “tear.” This type of injury pattern is classically seen in the pediatric population.
