Para-acetabular insufficiency fractures

Cooper et al (1985)
Associated with other pelvic insufficiency fractures
Causes include porosis, RA, RTP, steroids

Clinical features: severe hip and pelvic pain

Radiography:
Limited value, poor sensitivity
Band like or patchy subchondral sclerosis in paraacetabular area

CT:
Condensed sclerotic bone

Bone scintigraphy:
Intense tracer uptake in para-acetabular region

MRI:
Fracture seen as band of low signal on T1 and T2, surrounded by marrow edema seen as low signal on T1 and high signal on T2
Fracture line - curvilinear and parallel to acetabular roof, striaght and crossing acetabular roof in oblique way
Marked enhancement of adjacent area on Gd

References:
Theodorou SJ et al. Magnetic resonance imaging of para-acetabular insufficiency fractures in patients with malignancy . Clin Rad 2006: 181-190