Ankylosing Spondylitis

Question 1

HLA association

Answer 1

HLA B27

Question 2

Typical patient demographic presenting with Ankylosing spondylitis

Answer 2

males (sex ratio 3:1)
aged 20-30 years old.

Question 3

Common symptoms

Answer 3

young man
lower back pain and stiffness
insidious onset
stiffness worse in the morning and improves with exercise
pain at night which improves on getting up

Question 4

Examination findings

Answer 4

reduced lateral flexion
reduced forward flexion - Schober’s test
reduced chest expansion

Question 5

Other features of ankylosing spondylitis (the A’s)

Answer 5

Apical fibrosis
Anterior uveitis
Aortic regurgitation
Achilles tendonitis
AV node block
Amyloidosis
cauda equina syndrome
peripheral arthritis

Question 6

Blood tests are poor for diagnosing ankylosing spondylitis. TRUE/FALSE

Answer 6

TRUE
- inflammatory markers (CRP/ESR) are non-specific
- HLA-B27 is present in 90% patients with AS but also 10% of normal patients

Question 7

What imaging is most commonly used to diagnose ankylosing spondylitis?

Answer 7

Plain x-ray of the sacroiliac joints

Question 8

Describe the late XR changes seen in ankylosing spondylitis

Answer 8

sacroiliitis: subchondral erosions, sclerosis
squaring of lumbar vertebrae
‘bamboo spine’
syndesmophytes: ossification of outer fibers of annulus fibrosus
CXR may show apical fibrosis

Question 9

If X-Rays are negative for ankylosing spondylitis but you suspect it is early disease which may not appear, what imaging should be ordered next?

Answer 9

MRI
- can show early inflammation of sacroiliac joints

Question 10

How may spirometry aid a diagnosis of ankylosing spondylitis?

Answer 10

May show a restrictive defect due to a combination of
- pulmonary fibrosis
- kyphosis
- ankylosis of the costovertebral joints

Question 11

Management of ankylosing spondylitis

Answer 11

• encourage regular exercise such as swimming
• NSAIDs
• physio
• DMARDs if peripheral joint involvement
• Anti-TNF if severe disease refractory to other treatments