Ankylosing Spondylitis

Write about Ankylosing Spondylitis here.


• Typically a young man who presents with lower back pain and stiffness, or with asymmetrical large joint arthritis

• M:F = 8:1

• HLA-B27 (90-95%)

• Familial tendency - 1/4 relatives affected

• Usually presents before 45

• Stiffness usually worse in the morning and improves with activity

• Peripheral arthritis (25%, more common in females)


Other Features - The 'A's:

• Apical fibrosis

• Anterior uveitis

• Aortic regurgitation

• Achilles Tendonitis

• AV node block

• Amyloidosis

• And cauda equina syndrome


Clinical Tests:

Heel, hips and occiput - can put all against wall?

• Schober's Test

• mark a point at level of posterior iliac spines (dimples of Venus) and a point 10cm above (or 5cm below and 5cm above).  

• Then patient to bend forward 

• The increase in distance should be 8-10cm (<3 is very reduced)

• Then repeat at thoracic T1 and 20cm lower - increase should be 8cm.

• If not achieved - ank spond


X-Ray Features:

• Sacroilitis - subchondral erosions, sclerosis

• Squaring of lumbar vertebrae

• 'bamboo spine' (late and uncommon)