Osteitis condensans ilii

Osteitis condensans ilii is characterized by benign sclerosis of the ilium adjacent to the sacroiliac (SI) joint, typically bilateral and triangular in shape.

It is usually asymptomatic but uncommonly may cause lower back pain, with a frequency of about 1-2.5% 4.

The underlying etiology is believed to be mechanical stress across the sacroiliac joint. That it is most often seen in women who have given birth supports this hypothesis; however, men and nulliparous women can be affected 2-4

Sclerosis of the iliac side of the sacroiliac joint is seen, typically bilateral, symmetrical and triangular in shape 3,4. Lack of sacral involvement or joint space narrowing is considered diagnostic and thus, may obviate the need for further imaging 3. Unilateral disease has been reported.

It carries a benign prognosis and may even resolve spontaneously. 

The main differential diagnosis is a sacroiliitis, but with osteitis condensans ilii the SI joint itself is normal, with no irregularity, erosions, or loss of joint space.

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Article information

rID: 1792
Synonyms or Alternate Spellings:
  • OCI
  • hyperostosis triangularis ilii
  • iliitis condensans

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Cases and figures

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  • with annotation
    Case 8: with paraglenoidal sulci
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