Ankylosing Spondylitis Flashcards
What is ankylosing spondylitis? (AS)
- A chronic systemic inflammatory disease involving axial skeleton (spine) and SI joints of younger patients
- Develops in males more then women
- Progressive stiffness overtime (lack of ability to move the spine)
If there is a patient with AS what are some of the key features?
- Seronegative arthropathy (rf negative)
- Pain and progressive stiffening of the spine
- Late teens/early 20s onset
- Ascending involvement of the spine (low back, hip first then to upper back)
- May involve chest wall (decreased expansion)
What is the suspected cause of AS?
- A genetic predisposition, triggered by an environmental factor
- HLA-B27 (has a high incidence)
How does AS occur? (What are the steps to spinal fusion)
- Activated T-cells and macrophages found at sites of inflammation with expression of IL-1B and TNF-a
- The inflammatory cytokines cause erosion of cortical bone, new bone formation and loss of bone mass occur
What are the clinical manifestations of AS?
- Chronic LBP
*morning stiffness with decreased ROM, back pain radiates to the thighs - Stiffness decreases with exercise
- Patient is unable to put head down while supine
- Peripheral arthritis may develop
- Pulmonary fibrosis, aortitis, Achilles enthesitis, acture anterior uveitis (rare)
How does sacroiliitis present in patients with AS?
- Pain will radiate to the butt and upper posterior thighs
- Might be U/L initially
- Then becomes B/L and persistent
What are some symptoms of AS?
- Stiffness improves with exercises
- Painful hips, shoulders, asymmetrical arthritis of lower limbs prior to spinal involvement
- Cervical and thoracic pain and stiffness is frequent
- Enthesitis (pain near the insertion of tendons and ligaments)
- Chest pain aggravated by increasing intra-thoracic pressure
What are the common symptom presentation in males?
- Spine and pelvis more frequently involved
- Some involvement of hips, shoulders, and chest wall
- Overall more severe
What are the common symptom presentations in women?
- Pelvis
- Hips
- Knees
- Wrists
- Less severe involvement of the spine
What is enthesitis?
- Where the tendons and ligaments attach to a bone
- It is the hallmark of spondyloarthropathies
- *Inflammation of ligament and tendon
What are the peripheral manifestations of AS?
- Enthesitis
- Peripheral arthritis
- Dactylitis
What other clinical features could be present in AS?
- Asymptomatic GI inflammation present in 25-49% of AS
- 50-60% of AS have microscopic inflammatory lesions
- Anterior uveitis occurs in about 25%
- Constitutional Sx similar to RA are absent in most
*no fever, malaise, weight loss
Upon examining for AS what might you find?
- B/L SI joint tenderness
- Peripheral joint synovitis
*asymmetric, oligoarticular pattern (axial skeleton first) - Dactylitis of fingers and toes
- Thickened Achilles’ tendon, planter fasciitis, chest wall tenderness
What are the some advanced features of AS that you may see during a PE?
- Changes in posture-flattening
*flat in the lumbar area
*thoracic kyphosis may be exaggerated - C-spine limitation in ROM with fusion
What are the diagnostic test for AS?
- Schober’s test
*below 5cm is abnormal - Tragus to wall
- Chest expansion
What are some diagnostic tests that can help confirm the diagnosis of AS?
- HLA-B27 testing
- Increased ESR/ CRP
- Symptoms of inflammatory back pain
- Family history
- B/L sacroiliitis on XR or MRI
- Bamboo spine of X-ray
- Loss of normal curvature
- Rf, ANA, anti-CCP antibodies (negative)
- Anemia
What will imaging show for a patient with AS?
- SI joints show first changes
*bilateral and symmetric - Sclerosis of vertebral bodies followed by squaring
- Bamboo spine
What is bamboo spine?
- A repeated process of healing and bone formation
- The spine fuses together and expands laterally and downward
Is it okay to use HLA b27 typing for the main investigation of AS?
No
*its an additional test to help validate the diagnosis
What are some differential diagnoses of AS?
- Mechanical LBP
- RA
- Sacroiliitis
- ReA
- PsA
What is the management for AS?
- NSAIDs (essential, first line)
*Naproxen
*celecoxib (not as harsh on stomach)
*Ibuprofen - Anti TNF (infliximab, shows good symptom relief)
What type of treatment is not recommended for AS?
- DMARDs (worsens osteoporosis)
- Steroids
What types of surgeries are used for AS?
Surgery is rare
1. Hip arthroplasty
2. Corrective spinal osteotomy
What is the prognosis for AS?
- Depends on stage at diagnosis
- Initiation of effective therapy
- Worse in smokers (will lower blood supply and produce inflammation)
