Osteitis Condensans Ilii.

Osteitis Condensans Ilii (OCI) is a benign cause of axial low back pain. Although no clear etiology has been identified, the prevailing theory is that mechanical strain affects the auricular portion of the ilium and causes premature arthritis. The location of the sclerosis has been traditionally confined to the ilium and may give the false impression of sacro-iliac joint involvement. Clinicians must be guided by history, radiographic findings, and laboratory studies in differentiating OCI with other disorders; furthermore additional causes of low back pain including metastatic disease and ankylosing spondylitis must be ruled out. Treatments for the condition are primarily conservative (therapies, non-steroidal anti-inflammatory medications, and steroid injections), with surgical resection being reserved for refractory cases.