Ankylosing Spondylitis Flashcards
What does ankylosis mean
severe or complete loss of movement at a joint
What type of disease is ankylosing spondylitis
an inflammatory disease of unknown origin
What joints does ankylosing spondylitis usually affect
intervetebral (between vertebraes) and sacroiliac (between sacrum and hip)
How is AS characterised interms of pain and stiffness
Pain and stiffness in hips and lower back, that progresses upwards along spine/backbone
What does ankylosing spondylitis treatment consist of
anti-inflammatory drugs, heat, massage and supervised exercise
What is rheumatoid arthritis
systemic (many joints and systems involved) Inflammatory (chronic inflammatory mediators such as monocytes/lymphocytes involved) Autoimmune disease (immunoglobins and RF's) It is multisystem chronic synovitis that causes destruction and ankylosis of joints
How is RA involved with other diseases
Can get juvenile RA or stills disease (systemic-onset juvenile idopathic arthritis)
Multiple genes involved for disease onset
Feltys syndrome (long standing RA)–> pts have 3 conditions: RA, enlarged spleen and abnormally low blood count
AS
How does RA affect joints
High association with RF’s
inflammation in synovial membrane
leads to cartilage destruction
instability of joint
What gene increases the risk of an individual getting As
HLA-B27( increases risk by 90-95%)
It is a protein on the surface of WBC
Hence strong genetic predisposition for AS
Where does the inflammatory process generally begin in AS
Inflammation at enthesis(where ligament/tendon/capsule attaches to bone)
Inflammation here results in chemical and inflammatory mediators being at the site
Due to long term inflammation, the site becomes ossified and results in enthesitis (ossifying the ligament)
What is the process of joint fusion in AS
Enthesitis = fibrosis
Get fibrosis ankylosis–> a fibrous connective tissue process which results in decreased ROM
Proceeds to bony ankylosis/ossification–> osseous tissue fuses 2 bones together reducing mobility
Joint Fusion
What are the early signs of primary AS
Decreased ROM (later get a more distinct lack of ROM) Usually starts at the sacro-iliac joint--> get low back pain for no reason in young adolscents
Why is sacro-iliac joint affected first
due to most of load/weight of body being placed on SIJ, it is more susceptible to damage and hence increased risk of fusing
What is osseous tissue
tissue formed into bone, hence tissue is ossified
What does fibrosis of tissue mean
thickening and scaring of connective tissue
what is secondary AS
occurs in older age groups
assoicated with psoriasis (rash)–> a chronic autoimmune disease causing the rapid buildup of skin cells
Also associated with inflammatory bowel disease
What is the prevelance of AS
greater occurence in white males
Mainly european–> 15/20 - 40yrs (end of growth spurt=increased ossification)
mainly localised to spine–> SIJ first
Females: spine involvement not as much or as severe (less dramatic changes), possible peripheral joint involvement and less rapid progression
What does HLA stand for
Human leucocyte antigen
Found on surface of WBC
How does HLA-B27 affect the inflammatory process in AS
Misfolding of HLA-B27 in endoplasmic reticulum (ER) upsets the normal cellular functions and causes a stress response of ER–> upsets the activaitona nd accumulation of inflammatory cytokines
Inflammatory cells (mainly macrophages and lymphocytes=signs of chronic inflammation) accumulate in joint capsule, fibrocartilage, periosteum(enthesis) hence enthesitis
Macrophages and lymphocytes erode–> leaves fibrocartilage hence repair begins
Fibroblasts proliferate–> secrete and synthesis collagen
Collagen organises into fibrous scar tissue
Fibrous scar tissue and chronic inflammation ossifies/calcifies scar tissue
Bone increases and activates osteoblasts to lay down new matric
New matrix becomes callus - fibrous - osseous- bone - changes enthesis
This new enthesis is called a syndesmophyte
What are the signs and symptoms of AS
Inflammation causing lower back pain and stiffness
Sclerosis–> hardening of soft tissue (in x-ray sclerosis comes up as bright white)
Early 20’s is peak incidence
Lower back pain decreases with activity, however early morning stiffness present (occurs due to lying in one position)
These changes occur before x-ray changes are seen
Lumbar curvature flattens–> treatment is mobility, back extension
Thoracic curvature increased hence kyphotic
Hip and shoulders flexed as a result of joint fusion
How does AS cause respiratory problems
As AS moves up spine, and affects thoracic joints and spine, costotransverse, costosternal and costovertebral also fuse
This decreases chest mobility and ROM and hence the ability for lungs to fully expand and deflate during breathing (rigid chest wall)
As a result, not able to empty lungs out fully due to inability to perform forced expiration
Hence there is ‘leftover’ air in the lungs, which increase the chance of an infection
The rigidity of the chest wall also limits overall lung capacity which can result in shortness of breath, coughing etc
How can you examine AS
MRI
4 point test–> put occiput, shoulders, iliac crests and feet touching wall –> in AS one or more points will not touch
Wrigth-Schober test–> mark LS junction in stading and measure and mark 10cm above, get pt to flex at wait and normal increase in measurement is 5cm
What are some AS imaging procedures
MRI (able to see inflammation=early diagnosis)
X-ray (can see sclerosis)
Squaring of vertebrae–> closing of waits of vertebrae due to calcification of the spine ligaments which cause loss of anterior contour of spine, hence anterior longitudinal ligament affected
sclerosis of periarticular bone
Obliteration of joint space
Syndesmophytes
What is a physio treatment for AS
early diagnosis is better
Education
Continuous physio (continue ROM of spine and peripheral joints)
Physical therapy–> main skeletal mobility, prevent natural progression of contractures, prevention of deformity and maintenance of mobility require a continuous program, exercise performed several times a day
Maintain chest expansion, full extension of spine and complete ROM in proximal joints
Clinical visits and home programs–> monitor pt compliance
