Ankylosing Spondylitis Flashcards
What is the definition of Ankylosing Spondylitis?
Chronic progressive disease, characterized by inflammation of articular and para-articular structures –> progressive stiffening and axial fusion
What is the Modified New York Criteria for classification of Ankylosing Spondylitis?
Clinical feature
(a) Low back pain and stiffness for more than three months
(2) Limitation of motion of the lumbar spine in both the sagittal and frontal planes
(3) Limitations of chest expansion relative to normal values correlated for age and sex
Radiological criterion: Sacroiliitis grade >2 bilaterally or grade 3-4 unilaterally
Definite AS if the radiological criterion is associated with at least one clinical criterion.
How do you monitor the severity of ankylosing spondylitis?
Bath AS Disease Activity Index (BASDAI)
Score 1 to 10 of each of the 6 questions pertaining to the 5 major symptoms of AS. Average the 2 morning stiffness scores, add all up (0-50) and divide by 5 to get 0-10 score
≥ 4 = suboptimal control of disease
- Fatigue
- Spinal pain (neck, back hip pain)
- Joint pain/swelling other than spine
- Discomfort from areas of enthesitis
- Morning stiffness duration from time of waking up
- Morning stiffness severity from time of waking up
What are the clinical features of ankylosing spondylitis?
Recurrent & Episodic Inflammatory BACK pain & (+/- ALTERNATING) BUTTOCK Pain
- Pain is episodic! However, with Dz progression -> more persistent, Bilat & proximal
- Inflammatory Pain: Worse in the morning, better with exercise – some pt may have IBP
- One/both buttocks (may be alternating) +/- radiation to posterior thigh. Sacroiliitis is often the 1st PC of Ankylosing Spondylitis
+/- Is there neck pain? Is there increasing stiffness?
+/- peripheral joint involvement
- Asymmetrical, Bilateral , affects a few, predominantly large joints
- Some may start w peripheral jt pain eg LL monoarthritis, but pain will eventually involve the back
+/- Extra-skeletal features
- Fatigue, LOW
- 6 As
• Acute anterior uveitis (30%): Usually Abrupt & unilateral, severe eye pain, redness, photophobia and blurred vision = EMERGENCY
• Apical lung fibrosis (aka ILD)
• AR – early diastolic murmur
• AV conduction defects – 1st degree AV block
• Achilles tendinitis, plantar fasciitis – signs of Enthesitis
• Amyloidosis – infiltrative Dz causing IgA Nephropathy
What are the signs of ankylosing spondylitis?
Stiffness/reduced ROM: cervical (flexion/ extension/rotation), thoracic (rotation), lumbar (frontal/lateral flexion)
Schober’s test (<5cm)
Failed ‘wall test’ (Increased occiput-wall distance): loss of spine extension causing heels, buttocks, scapula and occiput to be unable to touch wall simultaneously
Reduced chest expansion (<2.5cm at 4th ICS) – not seen in other causes of acute back pain causing reduced ROM
In advanced disease,
- Stooped question mark posture - loss of lumbar lordosis, fixed thoracic kyphosis and loss of cervical extension + flexion of hip and knee (to maintain balance and upright posture)
- Paraspinal muscle wasting
What are the investigations to be performed for ankylosing spondylitis?
AP and lateral lumbar spine XR
- Lumbar XR preferred vs SIJ XR (not usually done), as lumbar XR can see both SIJ and lumbar spine, and has lower radiation especially to testes
- However, can consider Modified Ferguson view to look for early Sacro-iliitis changes
Test function
1) Sit cross legged (test FABER)
- Pain on FABER when tested leg remains above straight leg may indicate ipsilateral hip / SIJ patho
- Used to screen for Hip Pain / SIJ Dysfunction / AS / Iliopsoas Spasm
2) Ability to wear own pants
CXR: Costovert joint fusion (causing reduction in chest expansion) due to enthesitis
Labs (limited value)
- ↑ ESR/CRP in active phase -> NOT to monitor Dz Activity
- NCNC anaemia
Others
- SIJ injection (VIR guided LA): Pain relief on injection of LA is dx for SIJ disorders as cause of LBP
- HLA testing - may give supporting evidence in a difficult case, but not diagnostic
What are the AP and lateral lumbar spine XR findings in a patient with early AS?
- Sacro-ilitis: earliest sign!!
- Squaring of vertebral Bodies: loss of anterior concavity due to Anterior Longitudinal Ligament Ossification
- Shiny Corner Sign at margins of vertebral body: due to Enthesitis at insertion of annular fibrosis -> reactive sclerosis
- Marginal Syndesmophytes (often T11-L1 bilaterally)
Note: if suspecting non-radiographic axial SpA (presence of suggestive s/s w high CRP but normal XR, as inflammation is still in early stage) –> do MRI to confirm sacroiliitis, seen as bony edema
What are the AP and lateral lumbar spine XR findings in a patient with late AS?
- Vertebral scalloping, bamboo spine, dagger sign (ossified Posterior Longitudinal Ligament)
- Bilateral symmetrical SI erosions -> sclerosis -> joint space narrowing, ankyloses (best seen on Ferguson pelvic tilt view)
What history do you need to take in a patient with ankylosing spondylitis?
Presentation
- TRO neuro pain – ask about shooting pain / claudication); TRO Leriche syndrome (PVD) if only buttock pain
- Inflammatory vs Mechanical
- TRO other red flags – TRO Tumor, Infection, Trauma
- Age of patient – should be <45 YO
- Any buttock pain? Is it alternating? Is it intermittent?
- Any back pain? Neck Pain? Duration of Back pain should be >3 months
- Increasing stiffness?
- TRO other causes of inflamm back pain -> PAIRS
- Other joint involvement? should be peripheral large joints asymmetrically
Complications – think of the 6As
- Any Enthesitis? Pattern of Pain?
- Any redness of your eye?
- Any skin changes?
- Any dyspnoea?
- Chest Pain? (AR and AV conduction defects?)
- Other HLA-B27 manifestations – Eye, Liver, Skin (Dactylitis, Psoriasis), Joints (Peripheral large joints, asymmetrically), IBD
Family Hx
Functional Hx and Social Hx – cross legged, wear pants
What are the complications of Ankylosing Spondylitis?
Spinal fractures: higher chance w minor trauma, as fused spine is rigid, brittle and osteoporotic
- Typically in C5-7, but XR whole spine in AS accident victims
Anaesthesia: Issues w intubation (due to loss of cervical extension in late stages) and ventilation (due to decreased chest expansion)
What is the management for a patient with AS?
1) Education, exercise
- Both in ACTIVE and STABLE Dz!
- 30min, 5x /week. Group therapy increases compliance. (group therapy is especially useful in Ank Spond treatment)
- Active Activity > Passive Activity
- Land Based > Aquatic Activity
1st line: NSAIDs (pain relief) +/- local steroid injections
- For peripheral arthritis, Sacro-iliitis and Enthesitis
- Add on local steroid injections only if NSAIDs are insufficient
- Aims to improve sleep, pain control & exercise compliance during active inflamm
- Use of Systemic Steroids are not indicated
2nd line: TNF-α Inhibitors (disease modifying) Infliximab, adalimumab, etanercept
- For severe active AS if NSAIDs fail – if persistent /worsening S&S + ↑ BASDAI
- Rapid, dramatic, sustained reduction of symptoms (spinal and peripheral), improved fx and QOL; but does not reduce bony progression
- SLOWS but does not ST P -> hence train posture to allow good spinal fusion
- Relapse occurs on stopping therapy, but intermittent treatment is feasible
DMARDs may help peripheral arthritis but not spinal disease -> thus gd posture is impt
Synthetic DMARDs & other Biologics are not helpful for AS
Sx: Correct deformities eg cervical osteotomy for spinal deformities
What are the aims of exercise in AS?
- Prevent syndesmophyte formation
- Maintain spinal mobility, posture and chest expansion -> slow deterioration. Even if fusion, ensure fusion at optimum posture
- Provide symptom relief w exercise
What is the prognosis of AS?
Excellent (with exercise and pain relief), but prog is poorer if
- ESR >30
- Onset <16yo
- Early hip involvement
- Poor response to NSAIDs
Anti-TNF therapies are likely to ↓ morbidity, risk of permanent spinal stiffness and progressive peripheral joint disease
Patient education
- 50% chance of passing on HLA-B27 to children
- HLA-B27 +ve offspring have 30% chance of developing AS
