-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
1. OA: morning stiffness gets worse, RA: morning stiffness gets better
2. Both DIP and PIP in OA, no DIP in RA
1. Limited joints involved: DIP, PIP, knees, hips, lower spine
2. morning stiffness gets worse
3. osteophyte formation (classic nodes in DIP and PIP)
small bony growths, seen in OA
-what genetics associated with
-who typically affected
-women of late childbearing age
-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
Pannus, in Rheumatoid arthritis
-inflammed granulation tissue that fills joint space, created by synovitis
-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?
-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 factor: an IgM that binds to Fc portion of IgG
-marker of tissue damage
-characterized by (3)
-list them (4)
-group of joint disorders, characterized by:
1. no rheumatoid factor
3. HLA-B27 association
1. Psoriatic arthritis (sausage fingers/toes)
2. Ankylosing spondylitis (spine fused together)
3. Inflammatory Bowel Disease
4. Reiter Syndrome/Reactive arthritis (can't see, can't pee, can't climb a tree)
-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 to what? (3 disorders)
1. Leukemia, myeloproliferative disorders
-increased cell turnover means more DNA breakdown, leading to purine buildup
-loss of HGPRT means no salvage pathway for purines. More purines shunted into uric acid production
3. 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)
-seen in chronic gout
-white, chalky aggregates of urate crystals
-with fibrosis and giant cell reaction in soft tissue and joints
-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"
-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?
-also other larger joints: wrist, shoulder
What is CCP?
-Anti-cyclic citrullinated peptide
-measure this to diagnose RA. Better than Rheumatoid factor because sometimes RA has negative RF
-combination of RA and pneumoconiosis (lung disease caused by dust inhalation)
-presents with lung nodules on xray
In OA, bone/cartilage breaks allowing synovial fliud into subchondral space, forming cysts.
osteoarthritis: what do you see in synovial fluid?
-typically viscous and translucent, non-inflammatory WBC count (<2000/mm3)
-basically, you aspirate to exclude inflammatory causes of arthritis