Young male with pelvic pain, MRI revealed ankylosis of both sacroiliac joints with fatty metaplasia of the articulating surfaces. No signs of bone marrow edema to suggest active disease.

These findings are consistent with ankylosing spondylitis in a young male with chronic lower back pain, although a full clinical evaluation is necessary for diagnosis and to exclude other forms of axial spondyloarthritis.

Ankylosing spondylitis has a male predilection.