Ankylosing Spondylitis

Question 1

Define Ankylosing Spondylitis?

Answer 1

Seronegative inflammatory arthropathy affecting preferentially the axial skeletal and large proximal joints

Question 2

What is the aetiology of Ankylosing Spondylitis?

Answer 2

Strong association with the HLA-B27 gene (> 90% of cases are HLA-B27 positive)
Infective triggers and antigen-cross-reactivity with self-peptides have been hypothesised

Question 3

What is the pathophysiology of Ankylosing Spondylitis?

Answer 3

Inflammation starts at the entheses
Persistent inflammation leads to reactive new bone formation
Changes begin in the lumbar vertebrae and progress superiorly
Vertebral bodies become more square
Sysdesmophytes
Fusion of syndesmophytes and facet joints
Calcification of anterior and lateral spinal ligaments

Question 4

What are the entheses?

Answer 4

Where ligaments attach to vertebral bodies

Question 5

What are syndesmophytes?

Answer 5

Vertical ossifications bridging the margins between adjacent vertebrae

Question 6

What is the epidemiology of Ankylosing Spondylitis?

Answer 6

COMMON

Earlier presentation in males

Question 7

What are the presenting symptoms of Ankylosing Spondylitis?

Answer 7

Lower back and sacroiliac pain
Disturbed sleep
Progressive loss of spinal movement
Symptoms of asymmetrial peripheral arthritis
Pleuritic chest pain
Heel pain
Non-specific symptoms (e.g. malaise, fatigue)

Question 8

What is the pain pattern in Ankylosing Spondylitis?

Answer 8

Worse in the morning
Better with activity
Worse when resting

Question 9

What is the pleuritic chest pain due to in Ankylosing Spondylitis?

Answer 9

Costovertebral joint involvement

Question 10

What is the heel pain due to in Ankylosing Spondylitis?

Answer 10

Plantar fasciitis

Question 11

What are the signs of Ankylosing Spondylitis on physical examination?

Answer 11

Reduced range of spinal movement (particularly hip rotation)
Reduced lateral spinal flexion
Schober's Test 
Tenderness over the sacroiliac joints 
Signs of Extra-Articular Disease

Question 12

What is Schober’s Test?

Answer 12

Two fingers are placed on the patients back about 10 cm apart
The patient is asked to bend over
The distance between the two fingers should increase by > 5 cm on forward flexion

Question 13

What would you see on the Schober’s Test for Ankylosing Spondylitis?

Answer 13

Reduced movement

Question 14

What are the later stages of Ankylosing Spondylitis?

Answer 14

Thoracic kyphosis
Spinal fusion
Question mark posture

Question 15

What are the signs of Extra-Articular Disease in Ankylosing Spondylitis?

Answer 15

5 A's 
Anterior uveitis 
Apical lung fibrosis 
Achilles tendinitis 
Amyloidosis 
Aortic regurgitation

Question 16

What bloods do we do for Ankylosing Spondylitis?

Answer 16

FBC - anaemia of chronic disease
Rheumatoid factor - negative
ESR/CRP - high

Question 17

What are the different types of radiographs we do for Ankylosing Spondylitis?

Answer 17

Anteroposterior and lateral radiographs of the spine
Anteroposterior radiograph of sacroiliac joints
CXR

Question 18

What do we see on Anteroposterior and lateral radiographs of the spine for Ankylosing Spondylitis?

Answer 18

May show Bamboo spine

Question 19

What do we see on Anteroposterior radiograph of sacroiliac joints for Ankylosing Spondylitis?

Answer 19

Shows symmetrical blurring of joint margins

Question 20

Why would we do a CXR for Ankylosing Spondylitis?

Answer 20

Check for apical lung fibrosis

Question 21

What do we see on radiographs for the later stages of Ankylosing Spondylitis?

Answer 21

Erosions
Sclerosis
Sacroiliac joint function

Question 22

Why do we do Lung Function Tests for Ankylosing Spondylitis?

Answer 22

Assess mechanical ventilatory impairment due to kyphosis