Inflammatory Arthritides Flashcards
AS, RA, & OA
Describe a ‘swan neck deformity’
hyperextension at the PIP joint, flexion at the DIP joint
Describe a ‘boutonniere deformity’
flexion at PIP, hyperextension at DIP joint
What causes a swan neck deformity?
intrinsic hand muscle contracture (laxity of PIP joint w/ overstretched palmar plate & bow stringing of lat. band of extensor hood = hyperextension of PIP, flexion of DIP)
What causes a boutonniere deformity?
rupture of the central band of extensor hood (lat band of extensor hood = slip of PIP = flexion of PIP and extension of DIP).
What is an ‘ulnar drift deformity’?
ulnar deviation of the hand with subluxed MCP joints
What is a Baker’s cyst?
enlargement of the posterior knee bursa (may occur in RA impacted knee joints)
The inflammatory stage of AS usually ends by age…
40
AS synovitis usually begins at what joints, and then progresses…
SI joints, up the spine
90% of people diagnosed with AS have what in common?
HLA-B27 gene
Severe, longstanding AS can also see inflammation of the iris, which is called…
uveitis (present in up to 30% with AS)
How does AS change breathing?
it becomes primarily diaphragmatic as chest expansion is reduced
What is seen in 90% of RA cases after the first year?
the joints initially involved are the joints ultimately affected
True or false: in RA, joints are usually affected asymmetrically.
false. usually symmetrical
What is the role of proteolytic enzymes in RA?
attack and erode cartilage, eventually exposing subchondral bone
In severe cases of RA, erosion of what features in the neck can lead to cervical instability?
the alar ligament, transverse ligament, odontoid process
What is seen in RA - genu varus or valgus?
valgus