Differences between OCI and ankylosing spondylitis
OCI | Ankylosing spondylitis | |
---|---|---|
Age | Young adults | Young adults |
Sex | Common in women | Common in men |
Presentation | Usually after pregnancy | No specific correlation |
HLA-B27 | Usually absent | Present in 90% |
Spine involvement | Absent | Present |
Sacroiliac joint abnormality | ||
Distribution | Bilateral, symmetric; iliac | Bilateral, symmetric; iliac > sacrum |
Osteopenia | Absent | Present |
Sclerosis | Well defined | Poorly defined |
Joint space | Normal | Narrowed |
Erosion | Absent | Commonly seen |
Bony ankylosis | Absent | Common |