Ankylosing Spondylitis

Question 1

What is ankylosing spondylitis?

What does it cause?

Answer 1

Ankylosing spondylitis is one of a group of seronegative spondyloarthropathy conditions

it is an inflammatory condition, mainly affecting the spine, that causes progressive stiffness and pain

Question 2

Which gene are the seronegative spondylorthropathy conditions associated with?

Answer 2

HLA-B27 gene

Question 3

Which joints are affected in AS?

what can it progress to?

Answer 3

sacroiliac
vertebral column

can progress to fusion of the spine leading to bamboo spine finding on x-ray

Question 4

How does ankylosing spondylitis present?

Answer 4

typical exam presentation is young adult male, late teens or 20-30s

1. Lower back pain and stiffness and pain in sacroiliac region
2. stiffness >30 mins in the morning, improves of activity
3. insidious onset - > 3 months
4. patient may experience symptoms at night, improves with getting up
5. patient can experience flares in symptoms

Question 5

What examination findings would you expect to see in ankylosing spondylitis?

Answer 5

1. reduced lateral flexion
2. reduced forward flexion - Schober’s test (L5 vertebra measure 10cm above and 5 below, ask to bend forward, if distance <20 = restriction)
3. reduced chest expansion

Question 6

What are the other features of ankylosing spondylitis/assoiacted with, beyond spinal? 9

Answer 6

1. Apical fibrosis
2. Anterior uveitis
3. Aortic regurgitation
4. Enthesitis - Achilles tendonitis, plantar fasciitis
5. AV node block
6. Amyloidosis
7. Cauda equina syndrome
8. peripheral arthritis
9. IBD

Question 7

What are the investigations for ankylosing spondylitis?

Answer 7

• Inflammatory markers (CRP and ESR) may rise with disease activity
• HLA B27 genetic test
• Xray of the spine and sacrum, chest
• MRI of the spine can show bone marrow oedema early in the disease before there are any xray changes

Question 8

What are the plain film x-ray findings in ankylosing spondylitis? 5

Answer 8

1. Sacroilitis: subchondral erosions, sclerosis
2. squaring of the lumbar vertebrae - due to osteitis of anterior corners
3. syndesmophytes - bony growth (ossification) seen in the ligaments of the spine
4. Fusing - bamboo spine (late sign)
5. chest x-ray - apical fibrosis

Question 9

When should an MRI be done?

What can you expect to see on MRI

Answer 9

if x-ray is negative for AS changes but suspicion remains high MRI should be done

bone marrow oedema

Question 10

What might spirometry show?

Answer 10

restrictive defect due to combination of pulmonary fibrosis, kyphosis and ankylosis of the costovertebral joints

Question 11

What is the management of ankylosing spondylitis?

Answer 11

1. encourage regular exercise, avoid smoking
2. NSAIDs first line tx
3. Steroids - can be used for flare ups - rap, IM slow release or joint injections
4. Anti-TNF (etanercept) or monoclonal antibodies
   - disease modifying tx not useful if there is peripheral disease
5. physiotherapy
6. Bisphosphonates to treat osteoporosis

Question 12

Who is Anti-TNF recommended for?

Answer 12

those with persistently high disease despite conventional tx