1.3 Joints Flashcards
synovium
-what does it secrete
- inner lining of synovial joint capsule
- secretes fluid rich in hyaluronic acid for lubrication
How are symptoms different: osteoarthritis vs rheumatoid arthritis
-2 main symptoms
- OA: morning stiffness gets worse, RA: morning stiffness gets better
- Both DIP and PIP in OA, no DIP in RA
Osteoarthritis:
-symptoms
- Limited joints involved: DIP, PIP, knees, hips, lower spine
- morning stiffness gets worse
- osteophyte formation (classic nodes in DIP and PIP)
osteophyte
small bony growths, seen in OA
Rheumatoid Arthritis
- what genetics associated with
- who typically affected
HLA-DR4
-women of late childbearing age
Rheumatoid Arthritis
- classic hallmark
- mech
- synovitis leading to formation of pannus, which fills joint space
- pannus is inflamed granulation tissue and contains myofibroblasts, which contract
- contraction moves joint bones in different directions
- increased osteoclast activity erodes bone
- joint fusion
Pannus, in Rheumatoid arthritis
-inflammed granulation tissue that fills joint space, created by synovitis
Rheumatoid Arthritis
-how do arthritic symptoms manifest?
- morning stiffness, gets better
- fingers: symmetric PIP joints–swan-neck deformity. DIP spared.
- limb joints: wrist, elbows, ankles, knees
- what are rheumatoid nodules?
- where do they occur?
- cause?
- found in Rheumatoid arthritis
- central zone of fibrinoid necrosis surrounded by epitheloid histiocytes
- usually subcutaneous and over bony prominences, like knuckles and elbows. but also in visceral organs.
- caused by vascular damage from RA vasculitis.
Rheumatoid arthritis:
-lab findings
- Rheumatoid factor: an IgM that binds to Fc portion of IgG
- marker of tissue damage
Seronegative Spondyloarthropathies
- characterized by (3)
- list them (4)
- group of joint disorders, characterized by:
1. no rheumatoid factor
2. spine
3. HLA-B27 association
“PAIR”
- Psoriatic arthritis (sausage fingers/toes)
- Ankylosing spondylitis (spine fused together)
- Inflammatory Bowel Disease
- Reiter Syndrome/Reactive arthritis (can’t see, can’t pee, can’t climb a tree)
Infectious arthritis
- most common causes
- most common presentation
- most commonly caused by:
1. Gonnorhea–sexually active young adults
2. S Aureus -single joint, usually knee.
easy tx with Abx
Secondary gout
-secondary to what? (3 disorders)
- Leukemia, myeloproliferative disorders
- increased cell turnover means more DNA breakdown, leading to purine buildup - Lesch-Nyhan.
- loss of HGPRT means no salvage pathway for purines. More purines shunted into uric acid production - Renal insufficiency -unable to excrete uric acid
Acute gout symptoms
- Podagra (pain arthritis of big toe) from crystal depostion
- meat or alcohol consumption can precipitate arthritis
Chronic gout symptoms
- presence of tophi–chalky aggregates of urate crystals, with fibrosis and giant cell reaction in soft tissue/joints
- renal failure (uric acid crystals deposit in tubules)
Tophi
- seen in chronic gout
- white, chalky aggregates of urate crystals
- with fibrosis and giant cell reaction in soft tissue and joints
Gout:
-what do you see in synovial fluid?
- crystals, needle shaped
- have negative birefringence under polarized light
- “when crystals lay low (flat), they are yellow”
“yellow, parallel, allopurinol”
Pseudogout:
-what do you see in synovial fluid?
- crystals, rhomboid shaped
- (CPPD) calcium pyrophosphate dihydrate
- weakly positive birefringence under polarized light
DIP is spared in what joint disease?
RA. unlike OA, which affects both DIP and PIP
What disease has DIP as the joint most commonly affected?
Psoriatic arthritis (sausage fingers)
“can’t see, can’t pee, can’t climb a tree”
-Reiter’s syndrome (reactive arthritis)
DIP and PIP are both affected in what joint disease?
OA. in RA, DIP is spared.
how do gout crystals cause inflammation?
Phagocytosed MSU crystals induce monocyte to release IL1
what body part does pseudogout most commonly affect?
- knee
- also other larger joints: wrist, shoulder
