Pathoma: Joint Flashcards
Synovial joints usually have _____________ over the end of the bone.
articular cartilage (type II collagen)
The synovium along the internal edge of the joint capsule secretes ________________ to lubricate the joints.
hyaluronic acid
Degenerative joint disease usually presents as stiffness in the morning that _____________ throughout the day.
worsens
List the three classic histologic pathologies that present with degenerative joint disease.
- Destruction of the articular cartilage
- Eburnation (aka polishing) of the subchondral bone
- Osteophyte formation
Osteophytes classically present in the ______________.
DIPs and PIPs
Rheumatoid arthritis is classically associated with what HLA subtype?
HLA-DR4
The hallmark histologic pathology of rheumatoid arthritis is ______________.
synovitis that leads to destruction of the underlying
A pannus is a thick ___________ tissue layer.
granulation
What cells mediate ankylosis?
Ankylosis is fusion of joints. This is mediated by myofibroblasts in granulation tissue that contract and pull the joint together.
Note: if this fusion happens asymmetrically, it can produce distortion of the joint (such as a finger deviating off to one side).
The classic symptom of rheumatoid arthritis is joint stiffness that ____________ throughout the day.
improves
This occurs because of movement pushing the inflammatory infiltrate out.
List some of the extra-articular manifestations of rheumatoid arthritis.
- Rheumatoid nodules (necrotic granulomas in any tissue of the body)
- Vasculitis
- Pleural effusions
- Pulmonary fibrosis
- Baker cyst (inflammation of the knee bursa on the posterior aspect of the leg)
List the serum findings of rheumatoid arthritis.
- Rheumatoid factor (anti-IgG IgM) –very sensitive, not specific
- Anti-citrullinated peptide antibodies –very specific, not sensitive
Sattar didn’t mention the second one, but there is a UWorld question about it so it’s probably worth knowing.
Joint aspiration will show _____________ in rheumatoid arthritis.
neutrophils and protein… no bacteria
What are some long-term complications of rheumatoid arthritis?
- Anemia of chronic disease (from the chronic inflammatory state inducing hepcidin and subsequent iron-deficiency anemia)
- Amyloidosis: RA induces serum amyloid A –another inflammatory marker –that gets converted to amyloid in the periphery and can accumulate in deposits
The spondylopathies notably lack what serum marker?
Rheumatoid factor
This is why ankylosing spondylitis is called a “seronegative” arthropathy.
What two extra-articular manifestations are common in ankylosing spondylitis?
- Uveitis
* Aortitis (increased risk of aortic aneurysm and aortic insufficiency)
Give a brief rundown on reactive arthritis.
- Associated with HLA-B27
- Usually presents one to two weeks after a GI infection (Campylobacter) or Chlamydia trochomatis infection
- Signs include uveitis, urethritis, and arthritis (“Can’t see. Can’t pee. Can’t climb a tree.”)
What joints are affected in psoriatic arthritis?
- Axial
- Appendicular
- Fingers
Basically everything. The DIP is common and presents with a swollen, “sausage” finger.
Which two organisms are commonly implicated in septic arthritis?
- N. gonorrhoeae (young adults)
* S. aureus (children, older adults, and IV drug users)
What are the signs and symptoms of infectious arthritis?
- Single joint affected
- Limited range of motion
- Fever
- Leukocytosis
GMP gets broken down to guanine and AMP gets broken down to ___________.
hypoxanthine
The most common cause of gout is ____________.
idiopathic increase in uric acid
Lesch-Nyhan disorder results from a defect in the _____________ pathway.
purine salvage
List three causes of secondary gout.
- Leukemia and other myeloproliferative disorders (because of increased turnover of cells and consequent increased purine degradation)
- Lesch-Nyhan (inability to salvage purines leads to increased conversion to xanthine)
- Chronic renal failure (inability to excrete uric acid)
Why do alcohol and meat induce gout attacks?
- Meat intake: increased RNA and DNA from food leads to increased uric acid
- Alcohol competes with uric acid for secretion in the kidney, so alcohol leads to increased uric acid
Tophi are described as __________________________.
“white chalky deposits”
Pseudogout is made from ___________ crystals.
calcium pyrophosphate
