Do torn ligaments in the SIJ show up on x-ray?
Depends!! Most of the time with plane AP and Lateral films, they do not show up, mostly because of the position of these ligaments between the bones. SIJD was demonstrated back in about 1930 using stereoscopic x-rays, but nobody does that any more. Injecting dye into the SIJ will demonstrate if the capsule is torn, but you can have SIJD without a torn capsule. Diagnostic injections of anesthetic into the joint capsule may give a false negative reading. If you get relief from such an injection, it is likely that the injection leaked from a tear in the capsule to the adjacent affect tissue, but if you get no relief, it may be because you injected into an intact capsule and the anesthetic was held there. In that case, you could have SIJD with no torn capsule and no relief from the anesthetic and thus the test would be falsely negative for SIJD.
