Sacral insufficiency fracture

Discussion

• Typically, patients present with groin, low back, or buttock pain.
• Patients present with either no history of trauma or a history of low impact trauma.
• Causes
  • Postmenopausal osteoporosis (most common)
  • Senile osteoporosis
  • Pelvic irradiation
  • Corticosteroid therapy
  • Rheumatoid arthritis

Diagnostic Findings

Plain film

• The most common finding is a sclerotic band or line.
• Lytic fracture line or cortical break rarely is observed.

CT

• Sacral fractures typically are oriented vertically and located parallel to the sacroiliac joints.
• Linear fracture line with surrounding sclerosis is observed.

MRI

• Decreased signal on T1-weighted images and increased signal on T2-weighted images.
• Signal changes are seen as linear bands within the sacral ala and body and are parallel to the sacroiliac joints.
• On T2-weighted images, the fracture line may be seen if it is surrounded by adjacent marrow edema.

Nuclear Medicine

• H or "Honda sign" which indicated horizontal involvement of the sacrum and vertical involvement of the sacral ala
• The "dot and dash" pattern is another common appearance.

Images

Patient #1: Lower back pain. History of pelvic radiation therapy

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External Links

• Goldminer: Sacral insufficiency fracture

References

• Wilfred CG. E-medicine rads article