5. Seronegative Spondyloarthritis Flashcards
Generally, what is a seronegative spondyloarthritis?
Pathoma: group of joint disorders characterized by lack of rheumatic factor (–>seronegative), axial skel involvement (–>spondylo), and association with HLA-B27.
Lect: also involves asymmetric peripheral joints, enthesitis, occasional mucocutaneous, ocular, cardiac sx.
what is an enthesis?
site of insertion of a tendon, ligament, or joint capsule into bone. metabolically active site.
Clinical characteristics of spondyloarthritis?
asymmetric peripheral arthritis, sacroiliitis (may cause low back pain), enthesitis.
is there a genetic component to spondyloarthritis?
significant familial component due to association with HLA B27
general framework for thinking about the causes of spondyloarthritis?
genetic predisposition + environmental stimulus leads to inflammation, leads to ankylosis (bone formation)
what is a syndesmophyte?
Wiki: a bony growth originating inside a ligament, commonly seen in the ligaments of the spine, specifically the ligaments in the intervertebral joints leading to fusion of vertebrae. Syndesmophytes are pathologically similar to osteophytes.
what is the term for the ossification and other changes seen in the spines of patients with ankylosing spondyloarthritis? what is the cause?
“bamboo spine”
due to inflammation of the annulus fibros at its insertion site, resulting in its ossification and ultimate formation into a “syndesmophyte”, creating the appearance of a bamboo spine.
for pts with ankylosing spondyloarthritis, what is seen on imaging of the pelvis?
joint space narrowing, bony sclerosis around the SI joints.
Ankylosing Spondyloarthritis: pain is worst at what time of day?
morning, pain and stiffness, lasts over an hour
Ankylosing Spondyloarthritis: what can help the pain and stiffness?
exercise, naproxen (NSAID)
Ankylosing Spondyloarthritis: why are there different frequencies of this dz in different ethnic groups? what groups have high prev/low prev?
the prevalence generally mirrors the freq of HLA-B27 in the population –> low prev in africa, Japan; higher rates in Norway, arctic peoples
What % of pts with Ankylosing Spondyloarthritis have HLA B27?
85-95%
Sacroilitis in Ankylosing Spondyloarthritis: symmetric or asymmetric?
symmetric
other findings with Ankylosing Spondyloarthritis?
possible psoriasis, acute uveitis (eye), marginal syndesmophytes
what are the clinical criteria for diagnosing Ankylosing Spondyloarthritis?
- low back pain/stiffiness > 3 m
- limitation of lumbar flexion
- limited chest expansion
- Sacroiliitis on imaging (required, but may not appear for 7 yrs post dz onset)
Physical exams for Ankylosing Spondyloarthritis?
- occiput to wall distance
- chest expansion (nl 5 cm)
- Schober’s: lumbar spine lengthening with flexion
- FABER: hip movement, pain in contralat SI
What is a romanus lesion/erosion? what disease is it seen in?
Imaging finding: inflammation at the site of insertion of the annulus -> osteitis of the anterior vertebral margins. aka ‘shining corners’, aka syndesmophyte
seen in Ankylosing Spondyloarthritis
over time the syndesmophytes of Ankylosing Spondyloarthritis create what classic appearance?
‘bamboo spine’: ossification of the annulus