Ankylosing spondylitis Flashcards
what is the typical presentation of ankylosing spondylitis?
Lower back (Spine and sacroiliac joints) pain + stiffness which improve with activity => kyphosis / questionmark posture (bamboo spine), schober’s test + (5 A’s)
Define ankylosing spondylitis?
Seronegative chronic inflammatory arthropathy affecting preferentially the axial skeletal and large proximal joints
Part of a group of conditions termed ‘sero-negative spondyloarthropathies’ – these all involve the whole spine and mostly the sacro-iliac joint
Seronegative = rheumatoid factor -ve
summarise the epidemiology of ankylosing spondylitis?
COMMON
Earlier presentation in males
Usually 30yr old males
what are the presenting symptoms of ankylosing spondylitis?
Gradualonset
Lower back and sacroiliac pain
Disturbed sleep
Pain pattern
- Worse in the morning – stiffness
- Better with activity
- Worse when resting
Progressive loss of spinal movement
Enthesitis – lower limbs with heel, knee and ischial tuberoisity are most commonly affected
Symptoms of asymmetrical peripheral arthritis
Pleuritic chest pain (due to costovertebral joint involvement) => dyspnoea
Heel pain (due to plantar fasciitis)
Non-specific symptoms (e.g. malaise, fatigue)
Blindness due to acute iritis in 1/3 of patients
describe the disease course variablitiy of ankylosing spondylitis?
Some progress to kyphosis, neck hyper-extensionand spino-cranial ankyloses
Enthesitis (inflammation of site of insertion of tendon into bone) – especially Achilles tendonitis, plantar fasciitis, at tibial and iliac tuberosities and at iliac crests
describe the pathophysiology of ankylosing spondylitis?
Inflammation starts at the entheses (where ligaments attach to vertebral bodies)
Persistent inflammation leads to reactive new bone formation
Changes begin in the lumbar vertebrae and progress superiorly
Vertebral bodies become more square
Syndesmophytes (vertical ossifications bridging the margins between adjacent vertebrae)
Fusion of syndesmophytes and facet joints
Calcification of anterior and lateral spinal ligaments
what joints does ankylosing spondylitis mainly affect?
spine and sacroiliac
outline the aetiology of ankylosing spondylitis?
associated with HLA-27 gene
what are the seronegative spondylarthropathies associated with the HLA-B27 allele?
PEAR
Psoriatic arthritis
Enteropathic arthritis (IBD-related)
Ankylosing spondylitis
Reactive arthritis
what are the signs of ankylosing spondylitis on physical examination?
Reduced range of spinal movement (particularly hip rotation)
Reduced lateral spinal flexion
Schober’s Test- reduced movement shows ankylosing spondylitis
tenderness over sacroiliac joints
what are the later stages of ankylosing spondylitis?
Thoracic kyphosis
Spinal fusion
Question mark posture
describe the schober’s test and what is seen in ankylosing spondylitis?
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 > 15 cm on forward flexion
Reduced movement would suggest ankylosing spondylitis
what are the signs of extra-articular disease 5As
Anterior uveitis
Apical lung fibrosis
Achilles tendinitis
Amyloidosis - mucosal and skin lesions
Aortic regurgitation
(IBD and cauda equine syndrome)
what are the appopriate investigations for ankylosing spondylitis?
1) Pelvic X-ray– should be requested in all patients with inflammatory back pain
(MRImost sensitive and better at detecting early disease– used for evaluating response to treatmentmainly )
Bloods
lung function tests
describe the bloods?
FBC - anaemia of chronic disease
Rheumatoid factor - negative
ESR/CRP - high
HLA B27+ve but this is not diagnostic!!
what is seen on the anteriorposterior and lateral radiographs of the spine?
Sacroiliitis
Vertical syndesmophytes
Bony proliferations due to enthesitis between ligaments and vertebrae. These fuse with vertebral body above causing ankyloses.
In later stages, calcification of ligaments with ankyloses leads to bamboo spine appearance.
what is seen on the anteriorposterior radiographs of the spine?
Shows symmetrical blurring of joint margins
