ankylosing spondylitis

Question 1

what is the most common predisposing gene for AS?

Answer 1

HLA-B27

Question 2

what are the articular features of AS?

Answer 2

back pain and stiffness - radiates to hips/ buttocks
reduced ROM in spine
loss of lumbar lordosis
‘question mark posture’
peripheral synovitis- usually hip and knee

Question 3

What are the extra articular features of AS?

Answer 3

7As:
Anterior uveitis
Atlantoaxial subluxation
Aortic valve incompetence
AVN block
Apical lung fibrosis
Amyloidosis (rare and late stages)
Achilles tendinitis

Question 4

How can you test the degree of flexion of the spine?

Answer 4

Modified schobers test:
Mark across posterior superior iliac spine and 10cm above it
Ask them to max lean down
Distance should go to at least 13.5-15cm in health adult

Question 5

what is the pathophysiology of AS?

Answer 5

inflammation of sacroiliac joints - annulus fibrosis starts to calcify - bony bridges created between vertebral bodies (ankyloses)

Question 6

What are the risk factors for AS?

Answer 6

HLA-B27 gene
Men (3:1)
Age 17-35
Northern European

Question 7

what does x ray of AS show?

Answer 7

erosions of bone, widening of SI joints, Romanus lesions (squaring of vertebral bodies with shiny corners), bamboo spine at later stages

Question 8

what causes the appearance of bamboo spine?

Answer 8

ossification of longitudinal ligaments of the spine

Question 9

what bloods do you do for AS and their usual results?

Answer 9

FBC -normal
ESR/CRP - raised in active disease
ANA/RF - -ve
ALP - elevated

Question 10

what are the conservative managements for AS?

Answer 10

education
physiotherapy
exercise - hydrotherapy and swimming are great ones