Osteitis Condensans Ilii

Case contribution: Dr Radhiana Hassan

Clinical:

  • A 40 years old lady
  • Para 4
  • Presented with back pain for one month
  • Clinical examination is unremarkable
Radiograph of lumbosacral spine in AP and lateral views

Radiographic findings:

  • Bilateral almost symmetrical sclerotic changes at both sacro-iliac joints (yellow arrows)
  • Triangular in shape and more towards iliac side
  • No narrowing of the SI joint spaces
  • Well-corticated opacities at anterosuperior corner of L3 and L4 vertebrae (red arrows)
  • No reduction in vertebral body heights and intervertebral disc spaces
  • No soft tissue mass

Diagnosis: Osteitis condensans ilii and Limbus vertebrae

Discussion:

  • Osteitis condensans ilii is characterised by benign sclerosis of the ilium adjacent to the sacroiliac joint, typically bilateral and triangular in shape.
  • It is usually asymptomatic but may cause back pain in about 1-2.5%
  • The underlying aetiology is believed to be mechanical stress across the sacroiliac joint.┬áThat it is most often seen in women who have given birth supports this hypothesis; however, men and nulliparous women can be affected
  • Lack of sacral involvement or joint space narrowing is considered diagnostic and thus, may obviate the need for further imaging.
  • Unilateral disease has been reported.
  • It carries a benign prognosis and may even resolve spontaneously.
  • The main differential diagnosis is a sacroiliatis but as demonstrated in this case, the SI joint itself is normal, with no irregularity, erosions, or loss of joint space which are expected in sacroiliatis.
  • Limbus vertebra is a well-corticated unfused ossification centre
  • Anterior limbus vertebrae are generally asymptomatic and are detected incidentally.
  • Posterior limbus vertebrae are far less common but have been reported to cause nerve compression.

 

Author: radhianahassan