"sacrum: (sacral insufficiency fracture) usually vertically through the sacral ala, parallelling the sacroiliac joint, often with a transverse component - this pattern resembles the capital letter H, leading to the designation H sign (or Honda sign)"
"medial iliac: vertical fracture parallelling the sacroiliac joint"
"supra-acetabular region: about one-third are associated with sacral insufficiency fractures"
"iliac wing: oblique fracture through the iliac wing, orientated somewhat parallel to the iliac crest"
"pubic rami: nearly 90% of fractures at this site occur in conjunction with insufficiency fractures elsewhere within the pelvis"
"parasymphyseal: (parasymphyseal insufficiency fracture 4,5) also frequently associated with other pelvic insufficiency fractures"
"Pelvic insufficiency fractures are a relatively common subtype of insufficiency fracture, and are recognised as a major cause of low back, buttock and groin pain in susceptible populations."
"Plain film, MRI and scintigraphic appearance at the site of fracture are the same as with all insufficiency fractures. They often occur in characteristic locations and patterns within the pelvis, and are best detected and evaluated using bone scintigraphy and/or MRI. CT is a relatively insensitive method of detection. Pelvic insufficiency fractures are typically occult on plain film unless secondary remodelling has begun."