Osteitis pubis is commonly seen in young patients, characterized by chronic inflammation of the pubic symphysis with resultant erosive change, joint irregularity and sclerosis.
The most common causes include pregnancy/childbirth, athletic activity, urological or gynecological surgery, trauma, and inflammatory arthritis.
Osteitis condensans ilii is characterized by bilateral, triangular sclerosis of the posterior ilium usually with sparing of the apposing sacrum. Though typically incidental, this is thought to represent chronic stress reaction and may cause lower back pain.
The sacroiliac joints are common sites for osteoarthritis :
- Sacroiliac osteoarthritis is characterized by joint space narrowing, osteophyte formation, and sclerosis in elderly individuals.
Sacroiliitis is characterized by bilateral articular surface sclerosis and erosions: leading to complete ankylosis in advanced cases.
This is commonly the first manifestation of ankylosing spondylitis, reactive arthritis, IBD associated arthritis, and psoriatic arthritis.
If sacroiliitis is clinically suspected in the absence of radiographic findings, consider MRI to assess for active inflammation.
Consider sacroiliac septic arthritis if the contralateral joint is completely normal.