Intrafracture fluid: a new diagnostic sign of insufficiency fractures of the sacrum and ilium.

MRI is generally regarded as being sensitive but non-specific for the detection of insufficiency fractures affecting the sacrum and pelvic ring. The finding of intrafracture fluid is described in two elderly patients with insufficiency fractures. This MR feature is believed to be a new diagnostic sign of these fractures affecting the sacrum and ilium.