- Axial dominant spondyloarthropathy
- Males are more commonly affected
- HLA-B27 positive
- Family history often present
- Primary site: Enthesis (junction of bone & tendon)
- MC site involved: B/L sacroilitis.
- Marrow edema (Reversible)
- Marginal syndesmophyte
- Ankylosis (fusion of vertebral bodies).
- IOC is MRI (to detect sacroilitis early)
- X-ray features:
- Squaring of vertebral body:
- Romanus/ Shiny corner sign:
- Andersson lesion (Central erosion of vertebral endplate):
- Dagger sign (fusion of inter-spinous ligaments):
- Bamboo spine (Outermost fibres of annulus fibrosus are ossified):
Rx: Consider early use of DMARDs & Biological agents.